bump version to 10.2.0

ci: pin Nix version to avoid error
To 2.13.3
2023-04-12 12:49:39 -05:00 · 2023-04-12 12:49:39 -05:00 · 2023-04-12 12:49:36 -05:00 · 2023-04-12 12:49:04 -05:00 · 2023-04-12 09:52:08 -05:00 · 2023-04-12 09:52:08 -05:00
225 changed files with 25842 additions and 7125 deletions
@@ -1,9 +1,9 @@
 freebsd_instance:
-  image_family: freebsd-13-0
+  image_family: freebsd-13-1

 build_task:
  name: Build FreeBSD (Stack)
-  install_script: pkg install -y postgresql13-client hs-stack
+  install_script: pkg install -y postgresql13-client hs-stack git

  stack_cache:
    folders: /.stack
@@ -11,8 +11,10 @@ inputs:
 runs:
  using: composite
  steps:
-    - uses: cachix/install-nix-action@v16
-    - uses: cachix/cachix-action@v10
+    - uses: cachix/install-nix-action@v18
+      with:
+        install_url: https://releases.nixos.org/nix/nix-2.13.3/install
+    - uses: cachix/cachix-action@v12
      with:
        name: postgrest
        authToken: ${{ inputs.authToken }}
@@ -0,0 +1,63 @@
+#!/bin/bash
+
+# This script builds PostgREST in a remote ARM server
+
+[ -z "$1" ] && { echo "Missing 1st argument: PostgREST github commit SHA"; exit 1; }
+[ -z "$2" ] && { echo "Missing 2nd argument: Build environment directory name"; exit 1; }
+
+PGRST_GITHUB_COMMIT="$1"
+SCRIPT_DIR="$2"
+
+DOCKER_BUILD_DIR="$SCRIPT_DIR/docker-env"
+
+install_packages() {
+  sudo apt-get update -y
+  sudo apt-get upgrade -y
+  sudo apt-get install -y git build-essential curl libffi-dev libffi7 libgmp-dev libgmp10 libncurses-dev libncurses5 libtinfo5 llvm libnuma-dev zlib1g-dev libpq-dev jq gcc
+  sudo apt-get clean
+}
+
+install_ghcup() {
+  export BOOTSTRAP_HASKELL_NONINTERACTIVE=1
+  export BOOTSTRAP_HASKELL_MINIMAL=1
+  curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | sh
+  source ~/.ghcup/env
+}
+
+install_cabal() {
+  ghcup upgrade
+  ghcup install cabal 3.6.0.0
+  ghcup set cabal 3.6.0.0
+}
+
+install_ghc() {
+  ghcup install ghc 8.10.7
+  ghcup set ghc 8.10.7
+}
+
+install_packages
+
+# Add ghcup to the PATH for this session
+[ -f ~/.ghcup/env ] && source ~/.ghcup/env
+
+ghcup --version || install_ghcup
+cabal --version || install_cabal
+ghc --version || install_ghc
+
+cd ~/$SCRIPT_DIR
+
+# Clone the repository and build the project
+git clone https://github.com/PostgREST/postgrest.git
+cd postgrest
+git checkout $PGRST_GITHUB_COMMIT
+cabal v2-update && cabal v2-build
+
+# Copy the built binary to the Dockerfile directory
+PGRST_BIN=$(cabal exec which postgrest | tail -1)
+cp $PGRST_BIN ~/$DOCKER_BUILD_DIR
+
+# Move and compress the built binary
+mkdir -p ~/$SCRIPT_DIR/result
+mv $PGRST_BIN ~/$SCRIPT_DIR/result
+cd ~/$SCRIPT_DIR
+tar -cJf result.tar.xz result
@@ -0,0 +1,16 @@
+# PostgREST docker hub image
+
+FROM ubuntu:focal AS postgrest
+
+RUN apt-get update -y \
+    && apt install -y --no-install-recommends libpq-dev zlib1g-dev jq gcc libnuma-dev \
+    && apt-get clean \
+    && rm -rf /var/lib/apt/lists/*
+
+COPY postgrest /usr/bin/postgrest
+
+EXPOSE 3000
+
+USER 1000
+
+CMD postgrest
@@ -0,0 +1,50 @@
+#!/bin/bash
+
+# This script publishes the Docker ARM images to Docker Hub.
+
+[ -z "$1" ] && { echo "Missing 1st argument: PostgREST github commit SHA"; exit 1; }
+[ -z "$2" ] && { echo "Missing 2nd argument: Docker repo"; exit 1; }
+[ -z "$3" ] && { echo "Missing 3rd argument: Docker username"; exit 1; }
+[ -z "$4" ] && { echo "Missing 4th argument: Docker password"; exit 1; }
+[ -z "$5" ] && { echo "Missing 5th argument: Build environment directory name"; exit 1; }
+[ -z "$6" ] && { echo "Missing 6th argument: PostgREST version"; exit 1; }
+
+PGRST_GITHUB_COMMIT="$1"
+DOCKER_REPO="$2"
+DOCKER_USER="$3"
+DOCKER_PASS="$4"
+SCRIPT_DIR="$5"
+PGRST_VERSION="v$6"
+IS_PRERELEASE="$7"
+
+DOCKER_BUILD_DIR="$SCRIPT_DIR/docker-env"
+
+clean_env()
+{
+    sudo docker logout
+}
+
+# Login to Docker
+sudo docker logout
+{ echo $DOCKER_PASS | sudo docker login -u $DOCKER_USER --password-stdin; } || { echo "Couldn't login to docker"; exit 1; }
+
+trap clean_env sigint sigterm exit
+
+# Move to the docker build environment
+cd ~/$DOCKER_BUILD_DIR
+
+# Push final images to Docker hub
+# NOTE: This command publishes a separate ARM image because the builds cannot
+#       be added to the manifest if they are not in the registry beforehand.
+#       This image must be manually deleted from Docker Hub at the end of the process.
+sudo docker buildx build --build-arg PGRST_GITHUB_COMMIT=$PGRST_GITHUB_COMMIT \
+                         -t $DOCKER_REPO/postgrest:$PGRST_VERSION-arm \
+                         --push .
+
+# Add the arm images to the manifest
+# NOTE: This assumes that there already is a `postgrest:<version>` image
+#       for the amd64 architecture pushed to Docker Hub
+sudo docker buildx imagetools create --append -t $DOCKER_REPO/postgrest:$PGRST_VERSION $DOCKER_REPO/postgrest:$PGRST_VERSION-arm
+[ -z $IS_PRERELEASE ] && sudo docker buildx imagetools create --append -t $DOCKER_REPO/postgrest:latest $DOCKER_REPO/postgrest:$PGRST_VERSION-arm
+
+sudo docker logout
@@ -4,18 +4,20 @@ on:
  push:
    branches:
      - main
+      - rel-*
    tags:
      - v*
  pull_request:
    branches:
      - main
+      - rel-*

 jobs:
  Lint-Style:
    name: Lint & check code style
    runs-on: ubuntu-latest
    steps:
-      - uses: actions/checkout@v2.4.0
+      - uses: actions/checkout@v3
      - name: Setup Nix Environment
        uses: ./.github/actions/setup-nix
        with:
@@ -35,39 +37,19 @@ jobs:
        # https://github.com/actions/runner/issues/241#issuecomment-842566950
        shell: script -qec "bash --noprofile --norc -eo pipefail {0}"
    steps:
-      - uses: actions/checkout@v2.4.0
+      - uses: actions/checkout@v3
      - name: Setup Nix Environment
        uses: ./.github/actions/setup-nix
        with:
-          tools: tests withTools
+          tools: tests

-      - name: Run coverage (IO tests and Spec tests against PostgreSQL 14)
+      - name: Run coverage (IO tests and Spec tests against PostgreSQL 15)
        run: postgrest-coverage
      - name: Upload coverage to codecov
-        uses: codecov/codecov-action@v2.1.0
+        uses: codecov/codecov-action@v3.1.1
        with:
          files: ./coverage/codecov.json

-      - name: Run the spec tests against PostgreSQL 13
-        if: always()
-        run: postgrest-with-postgresql-13 postgrest-test-spec
-      - name: Run the spec tests against PostgreSQL 12
-        if: always()
-        run: postgrest-with-postgresql-12 postgrest-test-spec
-      - name: Run the spec tests against PostgreSQL 11
-        if: always()
-        run: postgrest-with-postgresql-11 postgrest-test-spec
-      - name: Run the spec tests against PostgreSQL 10
-        if: always()
-        run: postgrest-with-postgresql-10 postgrest-test-spec
-      - name: Run the spec tests against PostgreSQL 9.6
-        if: always()
-        run: postgrest-with-postgresql-9.6 postgrest-test-spec
-
-      - name: Run query cost tests against all PostgreSQL versions
-        if: always()
-        run: postgrest-with-all postgrest-test-querycost
-
      - name: Run doctests
        if: always()
        run: nix-shell --run postgrest-test-doctests
@@ -77,11 +59,39 @@ jobs:
        run: postgrest-test-spec-idempotence


+  Test-Pg-Nix:
+    strategy:
+      fail-fast: false
+      matrix:
+        pgVersion: [9.6, 10, 11, 12, 13, 14, 15]
+    name: Test PG ${{ matrix.pgVersion }} (Nix)
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        # Hack for enabling color output, see:
+        # https://github.com/actions/runner/issues/241#issuecomment-842566950
+        shell: script -qec "bash --noprofile --norc -eo pipefail {0}"
+    steps:
+      - uses: actions/checkout@v3
+      - name: Setup Nix Environment
+        uses: ./.github/actions/setup-nix
+        with:
+          tools: tests withTools
+
+      - name: Run spec tests
+        if: always()
+        run: postgrest-with-postgresql-${{ matrix.pgVersion }} postgrest-test-spec
+
+      - name: Run IO tests
+        if: always()
+        run: postgrest-with-postgresql-${{ matrix.pgVersion }} -f test/io/fixtures.sql postgrest-test-io
+
+
  Test-Memory-Nix:
    name: Test memory (Nix)
    runs-on: ubuntu-latest
    steps:
-      - uses: actions/checkout@v2.4.0
+      - uses: actions/checkout@v3
      - name: Setup Nix Environment
        uses: ./.github/actions/setup-nix
        with:
@@ -90,20 +100,23 @@ jobs:
        run: postgrest-test-memory


-  Build-Nix:
+  Build-Static-Nix:
    name: Build Linux static (Nix)
    runs-on: ubuntu-latest
    steps:
-      - uses: actions/checkout@v2.4.0
+      - uses: actions/checkout@v3
      - name: Setup Nix Environment
        uses: ./.github/actions/setup-nix
        with:
          authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
+          tools: tests

      - name: Build static executable
        run: nix-build -A postgrestStatic
+      - name: Check static executable
+        run: postgrest-check-static result/bin/postgrest
      - name: Save built executable as artifact
-        uses: actions/upload-artifact@v2.2.4
+        uses: actions/upload-artifact@v3
        with:
          name: postgrest-linux-static-x64
          path: result/bin/postgrest
@@ -112,7 +125,7 @@ jobs:
      - name: Build Docker image
        run: nix-build -A docker.image --out-link postgrest-docker.tar.gz
      - name: Save built Docker image as artifact
-        uses: actions/upload-artifact@v2.2.4
+        uses: actions/upload-artifact@v3
        with:
          name: postgrest-docker-x64
          path: postgrest-docker.tar.gz
@@ -131,22 +144,18 @@ jobs:
      fail-fast: false
      matrix:
        include:
-          - name: Linux & test
+          - name: Linux
            runs-on: ubuntu-latest
            cache: |
              ~/.stack
              .stack-work
-            test: true
-            pgdir: /usr/lib/postgresql
            artifact: postgrest-ubuntu-x64

-          - name: MacOS & test
+          - name: MacOS
            runs-on: macos-latest
            cache: |
              ~/.stack
              .stack-work
-            test: true
-            pgdir: /usr/local/Cellar/postgresql
            artifact: postgrest-macos-x64

          - name: Windows
@@ -155,18 +164,15 @@ jobs:
              ~\AppData\Roaming\stack
              ~\AppData\Local\Programs\stack
              .stack-work
-            deps: |
-              stack exec -- pacman -S mingw64/mingw-w64-x86_64-postgresql --noconfirm
-            # We'd need to make test/with_tmp_db run on Windows first
-            # test: true
+            deps: Add-Content $env:GITHUB_PATH $env:PGBIN
            artifact: postgrest-windows-x64

    name: Build ${{ matrix.name }} (Stack)
    runs-on: ${{ matrix.runs-on }}
    steps:
-      - uses: actions/checkout@v2.4.0
+      - uses: actions/checkout@v3
      - name: Stack working files cache
-        uses: actions/cache@v2.1.7
+        uses: actions/cache@v3
        with:
          path: ${{ matrix.cache }}
          key: ${{ runner.os }}-${{ hashFiles('stack.yaml.lock') }}
@@ -175,14 +181,8 @@ jobs:
        run: ${{ matrix.deps }}
      - name: Build with Stack
        run: stack build --local-bin-path result --copy-bins
-      - name: Run Spec tests with Stack
-        if: ${{ matrix.test }}
-        run: |
-          postgresql_bin="$(find ${{ matrix.pgdir }} -maxdepth 2 -type d -name bin | head -n 1)"
-          echo "Using PostgreSQL binaries at $postgresql_bin ..."
-          PATH="$postgresql_bin:$PATH" test/with_tmp_db stack test
      - name: Save built executable as artifact
-        uses: actions/upload-artifact@v2.2.4
+        uses: actions/upload-artifact@v3
        with:
          name: ${{ matrix.artifact }}
          path: |
@@ -190,24 +190,108 @@ jobs:
            result/postgrest.exe
          if-no-files-found: error

-
  Get-FreeBSD-CirrusCI:
    name: Get FreeBSD build from CirrusCI
    runs-on: ubuntu-latest
    steps:
-      - uses: actions/checkout@v2.4.0
+      - uses: actions/checkout@v3
      - name: Get FreeBSD executable from CirrusCI
        env:
          # GITHUB_SHA does weird things for pull request, so we roll our own:
          GITHUB_COMMIT: ${{github.event.pull_request.head.sha || github.sha}}
        run: .github/get_cirrusci_freebsd
      - name: Save executable as artifact
-        uses: actions/upload-artifact@v2.2.4
+        uses: actions/upload-artifact@v3
        with:
          name: postgrest-freebsd-x64
          path: postgrest
          if-no-files-found: error

+  Build-Cabal:
+    strategy:
+      matrix:
+        ghc: ['8.10.7', '9.2.4']
+      fail-fast: false
+    name: Build Linux (Cabal, GHC ${{ matrix.ghc }})
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: ghcup
+        run: |
+          ghcup install ghc ${{ matrix.ghc }}
+          ghcup set ghc ${{ matrix.ghc }}
+      - name: Copy cabal.project
+        run: |
+          cp cabal.project.non-nix cabal.project
+      - name: Cache
+        uses: actions/cache@v3
+        with:
+          path: ~/.cabal
+          key: ${{ runner.os }}-${{ matrix.ghc }}-${{ hashFiles('**/*.cabal') }}-${{ hashFiles('**/cabal.project') }}
+          restore-keys: |
+            ${{ runner.os }}-${{ matrix.ghc }}-
+      - name: Install dependencies
+        run: |
+          cabal update
+          cabal build --only-dependencies --enable-tests --enable-benchmarks
+      - name: Build
+        run: cabal build --enable-tests --enable-benchmarks all
+
+  Build-Cabal-Arm:
+    name: Build aarch64 (Cabal)
+    if: ${{ github.ref == 'refs/heads/main' || startsWith(github.ref, 'refs/tags/v') || startsWith(github.ref, 'refs/heads/rel-') }}
+    runs-on: ubuntu-latest
+    outputs:
+      remotepath: ${{ steps.Remote-Dir.outputs.remotepath }}
+    env:
+      GITHUB_COMMIT: ${{ github.sha }}
+    steps:
+      - uses: actions/checkout@v3
+      - id: Remote-Dir
+        name: Unique directory name for the remote build
+        run: echo "remotepath=postgrest-build-$(uuidgen)" >> "$GITHUB_OUTPUT"
+      - name: Copy script files to the remote server
+        uses: appleboy/scp-action@master
+        with:
+          host: ${{ secrets.SSH_ARM_HOST }}
+          username: ubuntu
+          key: ${{ secrets.SSH_ARM_PRIVATE_KEY }}
+          fingerprint: ${{ secrets.SSH_ARM_FINGERPRINT }}
+          source: ".github/scripts/arm/*"
+          target: ${{ steps.Remote-Dir.outputs.remotepath }}
+          strip_components: 3
+      - name: Build ARM
+        uses: appleboy/ssh-action@master
+        env:
+          REMOTE_DIR: ${{ steps.Remote-Dir.outputs.remotepath }}
+        with:
+          host: ${{ secrets.SSH_ARM_HOST }}
+          username: ubuntu
+          key: ${{ secrets.SSH_ARM_PRIVATE_KEY }}
+          fingerprint: ${{ secrets.SSH_ARM_FINGERPRINT }}
+          command_timeout: 120m
+          script_stop: true
+          envs: GITHUB_COMMIT,REMOTE_DIR
+          script: bash ~/$REMOTE_DIR/build.sh "$GITHUB_COMMIT" "$REMOTE_DIR"
+      - name: Download binaries from remote server
+        uses: nicklasfrahm/scp-action@main
+        with:
+          direction: download
+          host: ${{ secrets.SSH_ARM_HOST }}
+          username: ubuntu
+          key: ${{ secrets.SSH_ARM_PRIVATE_KEY }}
+          fingerprint: ${{ secrets.SSH_ARM_FINGERPRINT }}
+          source: "${{ steps.Remote-Dir.outputs.remotepath }}/result.tar.xz"
+          target: "result.tar.xz"
+      - name: Extract downloaded binaries
+        run: tar -xvf result.tar.xz && rm result.tar.xz
+      - name: Save aarch64 executable as artifact
+        uses: actions/upload-artifact@v2.3.1
+        with:
+          name: postgrest-ubuntu-aarch64
+          path: result/postgrest
+          if-no-files-found: error
+

  Prepare-Release:
    name: Prepare release
@@ -216,15 +300,17 @@ jobs:
    needs:
      - Lint-Style
      - Test-Nix
+      - Test-Pg-Nix
      - Test-Memory-Nix
-      - Build-Nix
+      - Build-Static-Nix
      - Build-Stack
-      - Get-FreeBSD-CirrusCI
+      #- Get-FreeBSD-CirrusCI
+      - Build-Cabal-Arm
    outputs:
      version: ${{ steps.Identify-Version.outputs.version }}
      isprerelease: ${{ steps.Identify-Version.outputs.isprerelease }}
    steps:
-      - uses: actions/checkout@v2.4.0
+      - uses: actions/checkout@v3
      - id: Identify-Version
        name: Identify the version to be released
        run: |
@@ -236,14 +322,14 @@ jobs:
            exit 1
          else
            echo "Version to be released is $cabal_version"
-            echo "::set-output name=version::$cabal_version"
+            echo "version=$cabal_version" >> "$GITHUB_OUTPUT"
          fi

          if [[ "$cabal_version" != *.*.*.* ]]; then
            echo "Version is for a full release (version does not have four components)"
          else
            echo "Version is for a pre-release (version has four components, e.g., 1.1.1.1)"
-            echo "::set-output name=isprerelease::1"
+            echo "isprerelease=1" >> "$GITHUB_OUTPUT"
          fi
      - name: Identify changes from CHANGELOG.md
        run: |
@@ -261,7 +347,7 @@ jobs:
          echo "Relevant extract from CHANGELOG.md:"
          cat CHANGES.md
      - name: Save CHANGES.md as artifact
-        uses: actions/upload-artifact@v2.2.4
+        uses: actions/upload-artifact@v3
        with:
          name: release-changes
          path: CHANGES.md
@@ -277,9 +363,9 @@ jobs:
    env:
      VERSION: ${{ needs.Prepare-Release.outputs.version }}
    steps:
-      - uses: actions/checkout@v2.4.0
+      - uses: actions/checkout@v3
      - name: Download all artifacts
-        uses: actions/download-artifact@v2.0.10
+        uses: actions/download-artifact@v3
        with:
          path: artifacts
      - name: Create release bundle with archives for all builds
@@ -299,14 +385,18 @@ jobs:
          tar cJvf "release-bundle/postgrest-v$VERSION-macos-x64.tar.xz" \
            -C artifacts/postgrest-macos-x64 postgrest

-          tar cJvf "release-bundle/postgrest-v$VERSION-freebsd-x64.tar.xz" \
-            -C artifacts/postgrest-freebsd-x64 postgrest
+          # TODO: Fix timeouts for FreeBSD builds in Cirrus
+          #tar cJvf "release-bundle/postgrest-v$VERSION-freebsd-x64.tar.xz" \
+          #  -C artifacts/postgrest-freebsd-x64 postgrest
+
+          tar cJvf "release-bundle/postgrest-v$VERSION-ubuntu-aarch64.tar.xz" \
+            -C artifacts/postgrest-ubuntu-aarch64 postgrest

          zip "release-bundle/postgrest-v$VERSION-windows-x64.zip" \
            artifacts/postgrest-windows-x64/postgrest.exe

      - name: Save release bundle
-        uses: actions/upload-artifact@v2.2.4
+        uses: actions/upload-artifact@v3
        with:
          name: release-bundle
          path: release-bundle
@@ -329,25 +419,29 @@ jobs:
  Release-Docker:
    name: Release on Docker Hub
    runs-on: ubuntu-latest
-    needs: Prepare-Release
+    needs:
+      - Build-Cabal-Arm
+      - Prepare-Release
    env:
+      GITHUB_COMMIT: ${{ github.sha }}
      DOCKER_REPO: postgrest
      DOCKER_USER: stevechavez
+      DOCKER_PASS: ${{ secrets.DOCKER_PASS }}
      VERSION: ${{ needs.Prepare-Release.outputs.version }}
      ISPRERELEASE: ${{ needs.Prepare-Release.outputs.isprerelease }}
    steps:
-      - uses: actions/checkout@v2.4.0
+      - uses: actions/checkout@v3
      - name: Setup Nix Environment
        uses: ./.github/actions/setup-nix
        with:
          tools: release
      - name: Download Docker image
-        uses: actions/download-artifact@v2.0.10
+        uses: actions/download-artifact@v3
        with:
          name: postgrest-docker-x64
      - name: Publish images on Docker Hub
        run: |
-          docker login -u "$DOCKER_USER" -p "${{ secrets.DOCKER_PASS }}"
+          docker login -u "$DOCKER_USER" -p "$DOCKER_PASS"
          docker load -i postgrest-docker.tar.gz

          docker tag postgrest:latest "$DOCKER_REPO/postgrest:v$VERSION"
@@ -361,13 +455,48 @@ jobs:
          else
            echo "Skipping pushing to 'latest' tag for v$VERSION pre-release..."
          fi
-      - name: Update descriptions on Docker Hub
+      - name: Publish images for ARM builds on Docker Hub
+        uses: appleboy/ssh-action@master
        env:
-          DOCKER_PASS: ${{ secrets.DOCKER_PASS }}
-        run: |
-          if [[ -z "$ISPRERELEASE" ]]; then
-            echo "Updating description on Docker Hub..."
-            postgrest-release-dockerhub-description
-          else
-            echo "Skipping updating description for pre-release..."
-          fi
+          REMOTE_DIR: ${{ needs.Build-Cabal-Arm.outputs.remotepath }}
+        with:
+          host: ${{ secrets.SSH_ARM_HOST }}
+          username: ubuntu
+          key: ${{ secrets.SSH_ARM_PRIVATE_KEY }}
+          fingerprint: ${{ secrets.SSH_ARM_FINGERPRINT }}
+          script_stop: true
+          envs: GITHUB_COMMIT,DOCKER_REPO,DOCKER_USER,DOCKER_PASS,REMOTE_DIR,VERSION,ISPRERELEASE
+          script: bash ~/$REMOTE_DIR/docker-publish.sh "$GITHUB_COMMIT" "$DOCKER_REPO" "$DOCKER_USER" "$DOCKER_PASS" "$REMOTE_DIR" "$VERSION" "$ISPRERELEASE"
+# TODO: Enable dockerhub description update again, once a solution for the permission problem is found:
+# https://github.com/docker/hub-feedback/issues/1927
+#      - name: Update descriptions on Docker Hub
+#        env:
+#          DOCKER_PASS: ${{ secrets.DOCKER_PASS }}
+#        run: |
+#          if [[ -z "$ISPRERELEASE" ]]; then
+#            echo "Updating description on Docker Hub..."
+#            postgrest-release-dockerhub-description
+#          else
+#            echo "Skipping updating description for pre-release..."
+#          fi
+
+  Clean-Arm-Server:
+    name: Remove copied files from server
+    needs:
+      - Build-Cabal-Arm
+      - Release-Docker
+    if: ${{ always() && (github.ref == 'refs/heads/main' || startsWith(github.ref, 'refs/tags/v') || startsWith(github.ref, 'refs/heads/rel-')) }}
+    runs-on: ubuntu-latest
+    env:
+      REMOTE_DIR: ${{ needs.Build-Cabal-Arm.outputs.remotepath }}
+    steps:
+      - uses: actions/checkout@v2.4.0
+      - name: Remove uploaded files from server
+        uses: appleboy/ssh-action@master
+        with:
+          host: ${{ secrets.SSH_ARM_HOST }}
+          username: ubuntu
+          key: ${{ secrets.SSH_ARM_PRIVATE_KEY }}
+          fingerprint: ${{ secrets.SSH_ARM_FINGERPRINT }}
+          envs: REMOTE_DIR
+          script: rm -rf $REMOTE_DIR
@@ -0,0 +1,34 @@
+name: Loadtest
+
+on:
+  push:
+    branches:
+      - main
+    tags:
+      - v*
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  Loadtest-Nix:
+    name: Loadtest (Nix)
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+      - name: Setup Nix Environment
+        uses: ./.github/actions/setup-nix
+        with:
+          tools: loadtest
+      - name: Run loadtest
+        run: |
+          postgrest-loadtest-against main
+          postgrest-loadtest-report > loadtest/loadtest.md
+      - name: Upload report
+        uses: actions/upload-artifact@v3
+        with:
+          name: loadtest.md
+          path: loadtest/loadtest.md
+          if-no-files-found: error
@@ -22,7 +22,7 @@ jobs:
          name: loadtest.md
          path: artifacts
      - name: Upload to GitHub Checks
-        uses: LouisBrunner/checks-action@v1.2.0
+        uses: LouisBrunner/checks-action@v1.5.0
        with:
          token: ${{ secrets.GITHUB_TOKEN }}
          sha: ${{ github.event.workflow_run.head_sha }}
@@ -21,3 +21,5 @@ __pycache__
 *.tix
 coverage
 .hpc
+loadtest
+.history
@@ -0,0 +1,70 @@
+# Architecture
+
+This document describes the high-level architecture of PostgREST.
+
+## Bird's Eye View
+
+```haskell
+postgrest :: Request -> Either Error SQLStatement -> Response
+```
+
+On the highest level, PostgREST processes an HTTP request, if it's accepted it builds a SQL statement for it, executes it, and produces a response.
+
+## Code Map
+
+This section talks briefly about various important modules.
+
+The starting point of the program is `main/Main.hs`, which calls `src/PostgREST/CLI.hs` which then calls `src/PostgREST/App.hs`.
+
+`App.hs` is then in charge of composing the different modules.
+
+### ApiRequest.hs
+
+PostgREST operates over two types of resources: database relations(tables or views) and database functions; providing different representations(depending on the media type)
+for them.
+
+This module is in charge of representing the operation over an `ApiRequest` type. It parses the URL querystring following PostgREST syntax, the request headers, and the request body
+(if possible it avoids parsing the body and sends it directly to the db).
+
+A request might be rejected at this level if it's invalid, e.g. providing an unknown media type to PostgREST or using an unknown HTTP method.
+
+### Plan.hs
+
+Using the Schema Cache, this module enables more complex functionality(like resource embedding) by enriching the ApiRequest. It generates Plan types(`ReadPlan`, `MutatePlan`)
+that then will be used to generate a SQL statement.
+
+A request might be rejected at this level if it's invalid, e.g. by doing resource embedding on a nonexistent resource.
+
+An OPTIONS request doesn't require a plan to be generated.
+
+### Query.hs
+
+This module constructs single SQL statements that can be parametrized and prepared. Only at this stage a PostgreSQL connection from the pool is used.
+
+A query might fail(and be rollbacked) at this level if it doesn't comply to certain conditions, e.g. by not returning a single row when a ``Accept: application/vnd.pgrst.object`` header is specified.
+
+An OPTIONS request doesn't require a query to be executed.
+
+### Response.hs
+
+This module constructs the HTTP response body with the right headers.
+
+It builds the OpenAPI response using the schema cache.
+
+### Auth.hs
+
+This module provides functions to deal with JWT authorization.
+
+### Workers.hs
+
+This spawns threads which are used to execute concurrent jobs.
+
+Jobs include connection recovery, a listener for the PostgreSQL LISTEN command, and an admin server.
+
+### SchemaCache.hs
+
+This queries the PostgreSQL system catalogs and caches the metadata into a SchemaCache type,
+
+### AppState.hs
+
+The state of the App which is kept across requests.
@@ -3,12 +3,179 @@
 All notable changes to this project will be documented in this file.
 This project adheres to [Semantic Versioning](http://semver.org/).

-## Unreleased
+## [10.2.0] - 2023-04-12

 ### Added

+ - #2663, Limit maximal postgresql connection lifetime - @robx
+   + New option `db-pool-max-lifetime` (default 30m)
+   + `db-pool-acquisition-timeout` is no longer optional and defaults to 10s
+   + Fixes postgresql resource leak with long-lived connections (#2638)
+
 ### Fixed

+ - #2667, Fix `db-pool-acquisition-timeout` not logging to stderr when the timeout is reached - @steve-chavez
+
+## [10.1.2] - 2023-02-01
+
+### Fixed
+
+ - #2565, Fix bad M2M embedding on RPC - @steve-chavez
+ - #2575, Replace misleading error message when no function is found with a hint containing functions/parameters names suggestions - @laurenceisla
+ - #2582, Move explanation about "single parameters" from the `message` to the `details` in the error output - @laurenceisla
+ - #2569, Replace misleading error message when no relationship is found with a hint containing parent/child names suggestions - @laurenceisla
+ - #1405, Add the required OpenAPI items object when the parameter is an array - @laurenceisla
+ - #2592, Add upsert headers for POST requests to the OpenAPI output - @laurenceisla
+ - #2623, Fix FK pointing to VIEW instead of TABLE in OpenAPI output - @laurenceisla
+ - #2622, Consider any PostgreSQL authentication failure as fatal and exit immediately - @michivi
+ - #2620, Fix `NOTIFY pgrst` not reloading the db connections catalog cache - @steve-chavez
+
+## [10.1.1] - 2022-11-08
+
+### Fixed
+
+ - #2548, Fix regression when embedding views with partial references to multi column FKs - @wolfgangwalther
+ - #2558, Fix regression when requesting limit=0 and `db-max-row` is set - @laurenceisla
+
+## [10.1.0] - 2022-10-28
+
+### Added
+
+ - #2348, Add `db-pool-acquisition-timeout` configuration option, time in seconds to wait to acquire a connection. - @robx
+
+### Fixed
+
+ - #2261, #2349, #2467, Reduce allocations communication with PostgreSQL, particularly for request bodies. - @robx
+ - #2401, #2444, Fix SIGUSR1 to fully flush connections pool. - @robx
+ - #2428, Fix opening an empty transaction on failed resource embedding - @steve-chavez
+ - #2455, Fix embedding the same table multiple times - @steve-chavez
+ - #2518, Fix a regression when embedding views where base tables have a different column order for FK columns - @wolfgangwalther
+ - #2458, Fix a regression with the location header when inserting into views with PKs from multiple tables - @wolfgangwalther
+ - #2356, Fix a regression in openapi output with mode follow-privileges - @wolfgangwalther
+ - #2283, Fix infinite recursion when loading schema cache with self-referencing view - @wolfgangwalther
+ - #2343, Return status code 200 for PATCH requests which don't affect any rows - @wolfgangwalther
+ - #2481, Treat computed relationships not marked SETOF as M2O/O2O relationship - @wolfgangwalther
+ - #2534, Fix embedding a computed relationship with a normal relationship - @steve-chavez
+ - #2362, Fix error message when [] is used inside select - @wolfgangwalther
+ - #2475, Disallow !inner on computed columns - @wolfgangwalther
+ - #2285, Ignore leading and trailing spaces in column names when parsing the query string - @wolfgangwalther
+ - #2545, Fix UPSERT with PostgreSQL 15 - @wolfgangwalther
+ - #2459, Fix embedding views with multiple references to the same base column - @wolfgangwalther
+
+### Changed
+
+ - #2444, Removed `db-pool-timeout` option, because this was removed upstream in hasql-pool. - @robx
+ - #2343, PATCH requests that don't affect any rows no longer return 404 - @wolfgangwalther
+ - #2537, Stricter parsing of query string. Instead of silently ignoring, the parser now throws on invalid syntax like json paths for embeddings, hints for regular columns, empty casts or fts languages, etc. - @wolfgangwalther
+
+### Deprecated
+
+ - #1385, Deprecate bulk-calls when including the `Prefer: params=multiple-objects` in the request. A function with a JSON array or object parameter should be used instead for a better performance.
+
+## [10.0.0] - 2022-08-18
+
+### Added
+
+ - #1933, #2109, Add a minimal health check endpoint - @steve-chavez
+   + For enabling this, the `admin-server-port` config must be set explictly
+   + A `<host>:<admin_server_port>/live` endpoint is available for checking if postgrest is running on its port/socket. 200 OK = alive, 503 = dead.
+   + A `<host>:<admin_server_port>/ready` endpoint is available for checking a correct internal state(the database connection plus the schema cache). 200 OK = ready, 503 = not ready.
+ - #1988, Add the current user to the request log on stdout - @DavidLindbom, @wolfgangwalther
+ - #1823, Add the ability to run postgrest without any configuration. - @wolfgangwalther
+   + #1991, Add the ability to run without `db-uri` using libpq's PG environment variables to connect. - @wolfgangwalther
+   + #1769, Add the ability to run without `db-schemas`, defaulting to `db-schemas=public`. - @wolfgangwalther
+   + #1689, Add the ability to run without `db-anon-role` disabling anonymous access. - @wolfgangwalther
+ - #1543, Allow access to fields of composite types in select=, order= and filters through JSON operators -> and ->>. - @wolfgangwalther
+ - #2075, Allow access to array items in ?select=, ?order= and filters through JSON operators -> and ->>. - @wolfgangwalther
+ - #2156, #2211, Allow applying `limit/offset` to UPDATE/DELETE to only affect a subset of rows - @steve-chavez
+   + It requires an explicit `order` on a unique column(s)
+ - #1917, Add error codes with the `"PGRST"` prefix to the error response body to differentiate PostgREST errors from PostgreSQL errors - @laurenceisla
+ - #1917, Normalize the error response body by always having the `detail` and `hint` error fields with a `null` value if they are empty - @laurenceisla
+ - #2176, Errors raised with `SQLSTATE` now include the message and the code in the response body - @laurenceisla
+ - #2236, Support POSIX regular expression operators for row filtering - @enote-kane
+ - #2202, Allow returning XML from RPCs - @fjf2002
+ - #2268, Allow returning XML from single-column queries - @fjf2002
+ - #2300, RPC POST for function w/single unnamed XML param #2300 - @fjf2002
+ - #1564, Allow geojson output by specifying the `Accept: application/geo+json` media type - @steve-chavez
+   + Requires postgis >= 3.0
+   + Works for GET, RPC, POST/PATCH/DELETE with `Prefer: return=representation`.
+   + Resource embedding works and the embedded rows will go into the `properties` key
+   + In case of multiple geometries in the same table, you can choose which one will go into the `geometry` key with the usual `?select` query parameter.
+ - #1082, Add security definitions to the OpenAPI output - @laurenceisla
+ - #2378, Support http OPTIONS method on RPC and root path - @steve-chavez
+ - #2354, Allow getting the EXPLAIN plan of a request by using the `Accept: application/vnd.pgrst.plan` header - @steve-chavez
+   + Only allowed if the `db-plan-enabled` config is set to true
+   + Can generate the plan for different media types using the `for` parameter: `Accept: application/vnd.pgrst.plan; for="application/vnd.pgrst.object"`
+   + Different options for the plan can be used with the `options` parameter: `Accept: application/vnd.pgrst.plan; options=analyze|verbose|settings|buffers|wal`
+   + The plan can be obtained in text or json by using different media type suffixes: `Accept: application/vnd.pgrst.plan+text` and `Accept: application/vnd.pgrst.plan+json`.
+ - #2144, Support computed relationships which allow extending and overriding relationships for resource embedding - @steve-chavez, @wolfgangwalther
+ - #1984, Detect one-to-one relationships for resource embedding - @steve-chavez
+   + Detected when there's a foreign key with a unique constraint or when a foreign key is also a primary key
+
+### Fixed
+
+ - #2058, Return 204 No Content without Content-Type for PUT - @wolfgangwalther
+ - #2107, Clarify error for failed schema cache load. - @steve-chavez
+   + From `Database connection lost. Retrying the connection` to `Could not query the database for the schema cache. Retrying.`
+ - #1771, Fix silently ignoring filter on a non-existent embedded resource - @steve-chavez
+ - #2152, Remove functions, which are uncallable because of unnamend arguments from schema cache and OpenAPI output. - @wolfgangwalther
+ - #2145, Fix accessing json array fields with -> and ->> in ?select= and ?order=. - @wolfgangwalther
+ - #2155, Ignore `max-rows` on POST, PATCH, PUT and DELETE - @steve-chavez
+ - #2254, Fix inferring a foreign key column as a primary key column on views - @steve-chavez
+ - #2070, Restrict generated many-to-many relationships - @steve-chavez
+   + Only adds many-to-many relationships when: a table has FKs to two other tables and these FK columns are part of the table's PK columns.
+ - #2278, Allow casting to types with underscores and numbers(e.g. `select=oid_array::_int4`) - @steve-chavez
+ - #2277, #2238, #1643, Prevent views from breaking one-to-many/many-to-one embeds when using column or FK as target - @steve-chavez
+    + When using a column or FK as target for embedding(`/tbl?select=*,col-or-fk(*)`), only tables are now detected and views are not.
+    + You can still use a column or an inferred FK on a view to embed a table(`/view?select=*,col-or-fk(*)`)
+ - #2317, Increase the `db-pool-timeout` to 1 hour to prevent frequent high connection latency - @steve-chavez
+ - #2341, The search path now correctly identifies schemas with uppercase and special characters in their names (regression) - @laurenceisla
+ - #2364, "404 Not Found" on nested routes and "405 Method Not Allowed" errors no longer start an empty database transaction - @steve-chavez
+ - #2342, Fix inaccurate result count when an inner embed was selected after a normal embed in the query string - @laurenceisla
+ - #2376, OPTIONS requests no longer start an empty database transaction - @steve-chavez
+ - #2395, Allow using columns with dollar sign($) without double quoting in filters and `select` - @steve-chavez
+ - #2410, Fix loop crash error on startup in Postgres 15 beta 3. Log: "UNION types \"char\" and text cannot be matched". - @yevon
+ - #2397, Fix race conditions managing database connection helper - @robx
+ - #2269, Allow `limit=0` in the request query to return an empty array - @gautam1168, @laurenceisla
+ - #2401, Ensure database connections can't outlive SIGUSR1 - @robx
+
+### Changed
+
+ - #2001, Return 204 No Content without Content-Type for RPCs returning VOID - @wolfgangwalther
+   + Previously, those RPCs would return "null" as a body with Content-Type: application/json.
+ - #2156, `limit/offset` now limits the affected rows on UPDATE/DELETE  - @steve-chavez
+   + Previously, `limit/offset` only limited the returned rows but not the actual updated rows
+ - #2155, `max-rows` is no longer applied on POST/PATCH/PUT/DELETE returned rows - @steve-chavez
+   + This was misleading because the affected rows were not really affected by `max-rows`, only the returned rows were limited
+ - #2070, Restrict generated many-to-many relationships - @steve-chavez
+   + A primary key that contains the foreign key columns is now needed for generating many-to-many relationships.
+ - #2277, Views now are not detected when embedding using the column or FK as target (`/view?select=*,column(*)`) - @steve-chavez
+   + This embedding form was easily made ambiguous whenever a new view was added.
+   + You can use computed relationships to keep this embedding form working
+ - #2312, Using `Prefer: return=representation` no longer returns a `Location` header - @laurenceisla
+ - #1984, For the cases where one to one relationships are detected, json objects will be returned instead of json arrays of length 1
+   + If you wish to override this behavior, you can use computed relationships to return arrays again
+
+## [9.0.1] - 2022-06-03
+
+### Fixed
+
+- #2165, Fix json/jsonb columns should not have type in OpenAPI spec - @clrnd
+- #2020, Execute deferred constraint triggers when using `Prefer: tx=rollback` - @wolfgangwalther
+- #2077, Fix `is` not working with upper or mixed case values like `NULL, TrUe, FaLsE` - @steve-chavez
+- #2024, Fix schema cache loading when views with XMLTABLE and DEFAULT are present - @wolfgangwalther
+- #1724, Fix wrong CORS header Authentication -> Authorization - @wolfgangwalther
+- #2120, Fix reading database configuration properly when `=` is present in value - @wolfgangwalther
+- #2135, Remove trigger functions from schema cache and OpenAPI output, because they can't be called directly anyway. - @wolfgangwalther
+- #2101, Remove aggregates, procedures and window functions from the schema cache and OpenAPI output. - @wolfgangwalther
+- #2153, Fix --dump-schema running with a wrong PG version. - @wolfgangwalther
+- #2042, Keep working when EMFILE(Too many open files) is reached. - @steve-chavez
+- #2147, Ignore `Content-Type` headers for `GET` requests when calling RPCs. - @laurenceisla
+    + Previously, `GET` without parameters, but with `Content-Type: text/plain` or `Content-Type: application/octet-stream` would fail with `404 Not Found`, even if a function without arguments was available.
+- #2239, Fix misleading disambiguation error where the content of the `relationship` key looks like valid syntax - @laurenceisla
+- #2294, Disable parallel GC for better performance on higher core CPUs - @steve-chavez
+- #1076, Fix using CPU while idle - @steve-chavez
+
 ## [9.0.0] - 2021-11-25

 ### Added
@@ -2,9 +2,6 @@

 [![Donate](https://img.shields.io/badge/Donate-Patreon-orange.svg?colorB=F96854)](https://www.patreon.com/postgrest)
 [![Donate](https://img.shields.io/badge/Donate-PayPal-green.svg)](https://www.paypal.me/postgrest)
-<a href="https://heroku.com/deploy?template=https://github.com/PostgREST/postgrest">
-  <img src="https://img.shields.io/badge/%E2%86%91_Deploy_to-Heroku-7056bf.svg" alt="Deploy">
-</a>
 [![Join the chat at https://gitter.im/begriffs/postgrest](https://img.shields.io/badge/gitter-join%20chat%20%E2%86%92-brightgreen.svg)](https://gitter.im/begriffs/postgrest)
 [![Docs](https://img.shields.io/badge/docs-latest-brightgreen.svg?style=flat)](http://postgrest.org)
 [![Docker Stars](https://img.shields.io/docker/pulls/postgrest/postgrest.svg)](https://hub.docker.com/r/postgrest/postgrest/)
@@ -1,59 +0,0 @@
-{
-  "name": "PostgREST",
-  "description": "RESTful API for any PostgreSQL database.",
-  "logo": "https://avatars2.githubusercontent.com/u/15115011",
-  "repository": "https://github.com/PostgREST/postgrest",
-  "env": {
-    "BUILDPACK_URL": {
-      "description": "Heroku buildpack for deploying Haskell applications",
-      "value": "https://github.com/PostgREST/postgrest-heroku"
-    },
-    "POSTGREST_VER": {
-      "description": "Version of PostgREST to deploy",
-      "value": "8.0.0"
-    },
-    "DB_URI": {
-      "description": "Database connection string, e.g. postgres://user:pass@xxxxxxx.rds.amazonaws.com/mydb",
-      "required": true
-    },
-    "DB_SCHEMA": {
-      "description": "The database schema to expose to REST clients. Tables, views and stored procedures in this schema will get API endpoints",
-      "required": true,
-      "value": "public"
-    },
-    "DB_ANON_ROLE": {
-      "description": "The database role to use when executing commands on behalf of unauthenticated clients",
-      "required": true
-    },
-    "DB_POOL": {
-      "description": "Number of connections to keep open in PostgREST’s database pool",
-      "required": false,
-      "value": "10"
-    },
-    "SERVER_PROXY_URI": {
-      "description": "Overrides the base URL used within the OpenAPI self-documentation hosted at the API root path",
-      "required": false
-    },
-    "JWT_SECRET": {
-      "description": "The secret used to decode JWT tokens clients provide for authentication",
-      "required": false
-    },
-    "SECRET_IS_BASE64": {
-      "description": "When this is set to true, the value derived from jwt-secret will be treated as a base64 encoded secret",
-      "required": false,
-      "value": "false"
-    },
-    "JWT_AUD": {
-      "description": "The audience that should be validated if the JWT token contains an aud claim",
-      "required": false
-    },
-    "MAX_ROWS": {
-      "description": "A hard limit to the number of rows PostgREST will fetch from a view, table, or stored procedure",
-      "required": false
-    },
-    "PRE_REQUEST": {
-      "description": "A schema-qualified stored procedure name to call right after switching roles for a client request",
-      "required": false
-    }
-  }
-}
@@ -0,0 +1,20 @@
+-- Settings to allow building with plain cabal. If this was
+-- named just cabal.project, it would interfere with the default
+-- nix build.
+
+packages: .
+
+-- Example of depending on a forked repository (the same dependency
+-- would be mentioned in nix/overlays/haskell-packages.nix and
+-- stack.yaml, and should refer to a main branch commit of the
+-- repository.
+--
+-- source-repository-package
+--  type: git
+--  location: https://github.com/PostgREST/hasql-pool.git
+--  tag: 4d462c4d47d762effefc7de6c85eaed55f144f1d
+
+source-repository-package
+  type: git
+  location: https://github.com/PostgREST/postgresql-libpq.git
+  tag: 890a0a16cf57dd401420fdc6c7d576fb696003bc
@@ -1,9 +1,11 @@
+{ system ? builtins.currentSystem }:
+
 let
  name =
    "postgrest";

  compiler =
-    "ghc8107";
+    "ghc924";

  # PostgREST source files, filtered based on the rules in the .gitignore files
  # and file extensions. We want to include as litte as possible, as the files
@@ -34,7 +36,8 @@ let
      allOverlays.build-toolbox
      allOverlays.checked-shell-script
      allOverlays.gitignore
-      allOverlays.postgresql-default
+      allOverlays.postgis
+      (allOverlays.postgresql-default { inherit patches; })
      allOverlays.postgresql-legacy
      allOverlays.postgresql-future
      (allOverlays.haskell-packages { inherit compiler; })
@@ -42,16 +45,17 @@ let

  # Evaluated expression of the Nixpkgs repository.
  pkgs =
-    import nixpkgs { inherit overlays; };
+    import nixpkgs { inherit overlays system; };

  postgresqlVersions =
    [
-      { name = "postgresql-14"; postgresql = pkgs.postgresql_14; }
-      { name = "postgresql-13"; postgresql = pkgs.postgresql_13; }
-      { name = "postgresql-12"; postgresql = pkgs.postgresql_12; }
-      { name = "postgresql-11"; postgresql = pkgs.postgresql_11; }
-      { name = "postgresql-10"; postgresql = pkgs.postgresql_10; }
-      { name = "postgresql-9.6"; postgresql = pkgs.postgresql_9_6; }
+      { name = "postgresql-15"; postgresql = pkgs.postgresql_15.withPackages (p: [ p.postgis p.pg_safeupdate ]); }
+      { name = "postgresql-14"; postgresql = pkgs.postgresql_14.withPackages (p: [ p.postgis p.pg_safeupdate ]); }
+      { name = "postgresql-13"; postgresql = pkgs.postgresql_13.withPackages (p: [ p.postgis p.pg_safeupdate ]); }
+      { name = "postgresql-12"; postgresql = pkgs.postgresql_12.withPackages (p: [ p.postgis p.pg_safeupdate ]); }
+      { name = "postgresql-11"; postgresql = pkgs.postgresql_11.withPackages (p: [ p.postgis p.pg_safeupdate ]); }
+      { name = "postgresql-10"; postgresql = pkgs.postgresql_10.withPackages (p: [ p.postgis p.pg_safeupdate ]); }
+      { name = "postgresql-9.6"; postgresql = pkgs.postgresql_9_6.withPackages (p: [ p.postgis p.pg_safeupdate ]); }
    ];

  patches =
@@ -64,7 +68,7 @@ let
  # Function that derives a fully static Haskell package based on
  # nh2/static-haskell-nix
  staticHaskellPackage =
-    import nix/static-haskell-package.nix { inherit nixpkgs compiler patches allOverlays; };
+    import nix/static-haskell-package.nix { inherit nixpkgs system compiler patches allOverlays; };

  # Options passed to cabal in dev tools and tests
  devCabalOptions =
@@ -123,6 +127,10 @@ rec {
  docker =
    pkgs.callPackage nix/tools/docker { postgrest = postgrestStatic; };

+  # Load testing tools.
+  loadtest =
+    pkgs.callPackage nix/tools/loadtest.nix { inherit withTools; };
+
  # Script for running memory tests.
  memory =
    pkgs.callPackage nix/tools/memory.nix { inherit postgrestProfiled withTools; };
@@ -145,8 +153,9 @@ rec {
      inherit postgrest devCabalOptions withTools;
      ghc = pkgs.haskell.compiler."${compiler}";
      inherit (pkgs.haskell.packages."${compiler}") hpc-codecov;
+      inherit (pkgs.haskell.packages."${compiler}") weeder;
    };

  withTools =
-    pkgs.callPackage nix/tools/withTools.nix { inherit postgresqlVersions; };
+    pkgs.callPackage nix/tools/withTools.nix { inherit devCabalOptions postgresqlVersions postgrest; };
 }
@@ -2,15 +2,11 @@

 module Main (main) where

-import qualified Data.Map.Strict as M
-
 import System.IO (BufferMode (..), hSetBuffering)

 import qualified PostgREST.App as App
 import qualified PostgREST.CLI as CLI

-import PostgREST.Config (readPGRSTEnvironment)
-
 import Protolude

 #ifndef mingw32_HOST_OS
@@ -20,8 +16,7 @@ import qualified PostgREST.Unix as Unix
 main :: IO ()
 main = do
  setBuffering
-  hasPGRSTEnv <- not . M.null <$> readPGRSTEnvironment
-  opts <- CLI.readCLIShowHelp hasPGRSTEnv
+  opts <- CLI.readCLIShowHelp
  CLI.main installSignalHandlers runAppInSocket opts

 installSignalHandlers :: App.SignalHandlerInstaller
@@ -149,13 +149,13 @@ the PostgREST repo. Paths are resolved relative to the repo root:
 $ cd src
 # Even though the current directory is ./src, the config path must still start
 # from the repo root:
-$ postgrest-run test/io-tests/configs/simple.conf
+$ postgrest-run test/io/configs/simple.conf
 ```

 ## Testing

-In nix-shell, you'll find utility scripts that make it very easy to run the
-Haskell test suite, including setting up all required dependencies and
+In nix-shell, you'll find utility scripts that make it very easy to run our
+test suite, including setting up all required dependencies and
 temporary test databases:

 ```bash
@@ -182,7 +182,49 @@ postgrest-test-io -k config
 # Run tests in parallel using xdist, specifying the number of processes:
 postgrest-test-io -n auto
 postgrest-test-io -n 8
+```

+The memory tests check that we don't surpass a memory threshold for big request bodies.
+
+```bash
+# Build the dependencies needed for the memory test
+nix-shell --arg memory true
+
+# Run the memory test
+postgrest-test-memory
+```
+
+The loadtests ensure that performance doesn't drop on a change. Underlyingly they use
+[vegeta](https://github.com/tsenart/vegeta).
+
+```bash
+# Run the loadtests on the latest commit(HEAD)
+postgrest-loadtest
+
+# You can loadtest comparing to a different branch
+postgrest-loadtest-against master
+
+# Produce a markdown report to be used on CI
+postgrest-loadtest-report
+```
+
+doctests for some of our modules are also available:
+
+```bash
+postgrest-test-doctest
+```
+
+## Code coverage
+
+Code coverage is available under the `postgrest-coverage` command. This will produce a `./coverage` directory that can be visualized with a simple http server.
+
+```bash
+# Will run all the tests and produce a coverage dir
+postgrest-coverage
+
+# Visualize the output
+cd coverage
+python -mSimpleHTTPServer 8080
 ```

 ## Linting and styling code
@@ -24,21 +24,22 @@ import qualified Data.Text                               as T
 import qualified Data.Text.IO                            as T
 import qualified Dot
 import qualified GHC
+import qualified GHC.Paths
 import qualified Language.Haskell.GHC.ExactPrint.Parsers as ExactPrint
 import qualified Options.Applicative                     as O
 import qualified System.FilePath                         as FP

-import Bag                        (bagToList)
 import Data.Aeson.Encode.Pretty   (encodePretty)
 import Data.Function              ((&))
 import Data.List                  (intercalate)
 import Data.Maybe                 (catMaybes, mapMaybe)
 import Data.Text                  (Text)
+import GHC.Data.Bag               (bagToList)
 import GHC.Generics               (Generic)
 import GHC.Hs.Extension           (GhcPs)
-import Module                     (moduleNameString)
-import OccName                    (occNameString)
-import RdrName                    (rdrNameOcc)
+import GHC.Types.Name.Occurrence  (occNameString)
+import GHC.Types.Name.Reader      (rdrNameOcc)
+import GHC.Unit.Module.Name       (moduleNameString)
 import System.Directory.Recursive (getFilesRecursive)
 import System.Exit                (exitFailure)

@@ -197,11 +198,11 @@ sourceSymbols source = do
      return $ concatMap (importSymbols source filepath . GHC.unLoc) hsmodImports

 -- | Parse a Haskell module
-parseModule :: String -> IO (GHC.HsModule GhcPs)
+parseModule :: FilePath -> IO GHC.HsModule
 parseModule filepath = do
-  result <- ExactPrint.parseModule filepath
+  result <- ExactPrint.parseModule GHC.Paths.libdir filepath
  case result of
-    Right (_, hsmod) ->
+    Right hsmod ->
      return $ GHC.unLoc hsmod
    Left errs ->
      fail $ "Errors with " <> show filepath <> ":\n    "
@@ -212,7 +213,6 @@ parseModule filepath = do
 -- If the import is a wildcard, i.e. no symbols are selected for import, then
 -- only one item is returned.
 importSymbols :: FilePath -> FilePath -> GHC.ImportDecl GhcPs -> [ImportedSymbol]
-importSymbols _ _  (GHC.XImportDecl _) = mempty
 importSymbols source filepath GHC.ImportDecl{..} =
  case ideclHiding of
    Just (hiding, syms) ->
@@ -16,15 +16,20 @@ let
  ghc = ghcWithPackages modules;
  hsie =
    runCommand "haskellimports" { inherit name src; }
-      "${ghc}/bin/ghc -O -Werror -Wall -package ghc $src -o $out";
+      ''
+        cd $TMP
+        cp $src $TMP/Main.hs
+        ${ghc}/bin/ghc -O -Werror -Wall -package ghc Main.hs -o Main
+        cp Main $out
+      '';
  bin =
    runCommand name { inherit hsie name; }
      ''
        mkdir -p $out/bin
        ln -s $hsie $out/bin/$name
      '';
-  bashCompletion =
+  bash-completion =
    runCommand "${name}-bash-completion" { inherit bin name; }
      "$bin/bin/$name --bash-completion-script $bin/bin/$name > $out";
 in
-hsie // { inherit bashCompletion bin; }
+hsie // { inherit bash-completion bin; }
@@ -1,6 +1,6 @@
 # Pinned version of Nixpkgs, generated with postgrest-nixpkgs-upgrade.
 {
-  date = "2021-11-02";
-  rev = "7053541084bf5ce2921ef307e5585d39d7ba8b3f";
-  tarballHash = "1flhh5d4zy43x6060hvzjb5hi5cmc51ivc0nwmija9n8d35kcc4x";
+  date = "2023-01-12";
+  rev = "92f9580a4c369b4b51a7b6a5e77da43720134c9f";
+  tarballHash = "0w9bz4f2bmkj4a59n4z279zcgs9clyc40a4ny312rafyaknzghvw";
 }
@@ -1,11 +1,11 @@
-# Creates an environment that exposes bashCompletion arguments from all checkedShellScripts
+# Creates an environment that exposes bash-completion arguments from all checkedShellScripts
 { buildEnv }:
 { name
 , tools
 , extra ? { }
 }:
 let
-  bashCompletion = builtins.map (tool: tool.bashCompletion) tools;
+  bash-completion = builtins.map (tool: tool.bash-completion) tools;

  env = buildEnv {
    inherit name;
@@ -13,4 +13,4 @@ let
  };

 in
-env // { inherit bashCompletion; } // extra
+env // { inherit bash-completion; } // extra
@@ -2,7 +2,7 @@
 # directly, or use the .bin attribute to get the script in a bin/ directory,
 # to be used in a path for example.
 { argbash
-, bash_5
+, bash
 , coreutils
 , git
 , lib
@@ -14,7 +14,7 @@
 { name
 , docs
 , args ? [ ]
-, addCommandCompletion ? false
+, positionalCompletion ? ""
 , inRootDir ? false
 , redirectTixFiles ? true
 , withEnv ? null
@@ -22,11 +22,10 @@
 , withTmpDir ? false
 }: text:
 let
+  # square brackets are a pain to escape - if even possible. just don't use them...
+  escape = builtins.replaceStrings [ "\n" ] [ " \\n" ];
+
  argsTemplate =
-    let
-      # square brackets are a pain to escape - if even possible. just don't use them...
-      escapedDocs = builtins.replaceStrings [ "\n" ] [ " \\n" ] docs;
-    in
    writeTextFile {
      inherit name;
      destination = "/${name}.m4"; # destination is needed to have the proper basename for completion
@@ -37,7 +36,7 @@ let
          # stripping the /nix/store/... path for nicer display
          BASH_ARGV0="$(basename "$0")"

-          # ARG_HELP([${name}], [${escapedDocs}])
+          # ARG_HELP([${name}], [${escape docs}])
          ${lib.strings.concatMapStrings (arg: "# " + arg) args}
          # ARG_POSITIONAL_DOUBLEDASH()
          # ARG_DEFAULTS_POS()
@@ -59,14 +58,14 @@ let
        sed '/_positionals_count + 1/a\\t\t\t\tset -- "''${@:1:1}" "--" "''${@:2}"' -i $out
      '';

-  bashCompletion =
+  bash-completion =
    runCommand "${name}-completion" { } (
      ''
        ${argbash}/bin/argbash --type completion --strip all ${argsTemplate}/${name}.m4 > $out
      ''

-      + lib.optionalString addCommandCompletion ''
-        sed 's/COMPREPLY.*compgen -o bashdefault .*$/_command/' -i $out
+      + lib.optionalString (positionalCompletion != "") ''
+        sed 's#COMPREPLY.*compgen -o bashdefault .*$#${escape positionalCompletion}#' -i $out
      ''
    );

@@ -78,7 +77,7 @@ let

      text =
        ''
-          #!${bash_5}/bin/bash
+          #!${bash}/bin/bash
          source ${argsParser}
          set -euo pipefail
        ''
@@ -139,4 +138,4 @@ let
  script =
    runCommand name { inherit bin name; } "ln -s $bin/bin/$name $out";
 in
-script // { inherit bin bashCompletion; }
+script // { inherit bin bash-completion; }
@@ -3,6 +3,7 @@
  checked-shell-script = import ./checked-shell-script;
  gitignore = import ./gitignore.nix;
  haskell-packages = import ./haskell-packages.nix;
+  postgis = import ./postgis.nix;
  postgresql-default = import ./postgresql-default.nix;
  postgresql-legacy = import ./postgresql-legacy.nix;
  postgresql-future = import ./postgresql-future.nix;
@@ -12,8 +12,8 @@ self: super:
      gitignoreSrc = super.fetchFromGitHub {
        owner = "hercules-ci";
        repo = "gitignore";
-        rev = "211907489e9f198594c0eb0ca9256a1949c9d412";
-        sha256 = "06j7wpvj54khw0z10fjyi31kpafkr6hi1k0di13k1xp8kywvfyx8";
+        rev = "a20de23b925fd8264fd7fad6454652e142fd7f73";
+        sha256 = "sha256-8DFJjXG8zqoONA1vXtgeKXy68KdJL5UaXR8NtVMUbx8=";
      };
    in
    (super.callPackage gitignoreSrc { }).gitignoreSource;
@@ -13,21 +13,49 @@ let
      #       {
      #         pkg = "protolude";
      #         ver = "0.3.0";
-      #         sha256 = "0iwh4wsjhb7pms88lw1afhdal9f86nrrkkvv65f9wxbd1b159n72";
+      #         sha256 = "<sha256>";
      #       }
      #       { };
      #
-      # To get the sha256:
-      #   nix-prefetch-url --unpack https://hackage.haskell.org/package/protolude-0.3.0/protolude-0.3.0.tar.gz
+      # To temporarily pin unreleased versions from GitHub:
+      #   <name> =
+      #     prev.callCabal2nixWithOptions "<name>" (super.fetchFromGitHub {
+      #       owner = "<owner>";
+      #       repo  = "<repo>";
+      #       rev = "<commit>";
+      #       sha256 = "<sha256>";
+      #    }) "--subpath=<subpath>" {};
+      #
+      # To fill in the sha256:
+      #   update-nix-fetchgit nix/overlays/haskell-packages.nix

-      hasql-dynamic-statements =
-        lib.dontCheck (lib.unmarkBroken prev.hasql-dynamic-statements);
+      postgresql-libpq = lib.dontCheck
+        (prev.callCabal2nix "postgresql-libpq"
+          (super.fetchFromGitHub {
+            owner = "PostgREST";
+            repo = "postgresql-libpq";
+            rev = "890a0a16cf57dd401420fdc6c7d576fb696003bc"; # master
+            sha256 = "1wmyhldk0k14y8whp1p4akrkqxf5snh8qsbm7fv5f7kz95nyffd0";
+          })
+          { });

-      hasql-implicits =
-        lib.dontCheck (lib.unmarkBroken prev.hasql-implicits);
+      hasql-notifications = lib.dontCheck
+        (prev.callHackageDirect
+          {
+            pkg = "hasql-notifications";
+            ver = "0.2.0.4";
+            sha256 = "sha256-fm1xiDyvDkb5WLOJ73/s8wrWEW23XFS7luAv2brfr8I=";
+          }
+          { });

-      ptr =
-        lib.dontCheck (lib.unmarkBroken prev.ptr);
+      hasql-pool = lib.dontCheck
+        (prev.callHackageDirect
+          {
+            pkg = "hasql-pool";
+            ver = "0.9";
+            sha256 = "sha256-5UshbbaBVY8eJ/9VagNVVxonRwMcd7UmGqDc35pJNFY=";
+          }
+          { });
    } // extraOverrides final prev;
 in
 {
@@ -0,0 +1,27 @@
+final: prev:
+let
+  postgis_3_2_3 = rec {
+    version = "3.2.3";
+    src = final.fetchurl {
+      url = "https://download.osgeo.org/postgis/source/postgis-${version}.tar.gz";
+      sha256 = "sha256-G02LXHVuWrpZ77wYM7Iu/k1lYneO7KVvpJf+susTZow=";
+    };
+  };
+in
+{
+  postgresql_11 = prev.postgresql_11.override { this = final.postgresql_11; } // {
+    pkgs = prev.postgresql_11.pkgs // {
+      postgis = prev.postgresql_11.pkgs.postgis.overrideAttrs (_: postgis_3_2_3);
+    };
+  };
+  postgresql_10 = prev.postgresql_10.override { this = final.postgresql_11; } // {
+    pkgs = prev.postgresql_10.pkgs // {
+      postgis = prev.postgresql_10.pkgs.postgis.overrideAttrs (_: postgis_3_2_3);
+    };
+  };
+  postgresql_9_6 = prev.postgresql_9_6.override { this = final.postgresql_11; } // {
+    pkgs = prev.postgresql_9_6.pkgs // {
+      postgis = prev.postgresql_9_6.pkgs.postgis.overrideAttrs (_: postgis_3_2_3);
+    };
+  };
+}
@@ -1,5 +1,8 @@
-self: super:
+{ patches }: self: super:
 # Overlay that sets the default version of PostgreSQL.
+with patches;
 {
-  postgresql = super.postgresql_14;
+  postgresql = super.postgresql_15.overrideAttrs ({ patches ? [ ], ... }: {
+    patches = patches ++ [ postgresql-atexit ];
+  });
 }
@@ -2,19 +2,33 @@ self: super:
 # Overlay that adds legacy versions of PostgreSQL that are supported by
 # PostgREST.
 {
-  # PostgreSQL 9.5 was removed from Nixpkgs with
-  # https://github.com/NixOS/nixpkgs/commit/72ab382fb6b729b0d654f2c03f5eb25b39f11fbb
+  # PostgreSQL 9.6 was removed from Nixpkgs with
+  # https://github.com/NixOS/nixpkgs/commit/757dd008b2f2926fc0f7688fa8189f930ea47521
  # We pin its parent commit to get the last version that was available.
-  # postgresql_9_5 =
-  #  let
-  #    rev = "55ac7d4580c9ab67848c98cb9519317a1cc399c8";
-  #    tarballHash = "02ffj9f8s1hwhmxj85nx04sv64qb6jm7w0122a1dz9n32fymgklj";
-  #
-  #    pinnedPkgs =
-  #      builtins.fetchTarball {
-  #        url = "https://github.com/nixos/nixpkgs/archive/${rev}.tar.gz";
-  #        sha256 = tarballHash;
-  #      };
-  #  in
-  #  (import pinnedPkgs { }).pkgs.postgresql_9_5;
+  postgresql_9_6 =
+    let
+      rev = "571cbf3d1db477058303cef8754fb85a14e90eb7";
+      tarballHash = "0q74wn418i1bn5sssacmw8ykpmqvzr0s93sj6pbs3rf6bf134fkz";
+      pinnedPkgs =
+        builtins.fetchTarball {
+          url = "https://github.com/nixos/nixpkgs/archive/${rev}.tar.gz";
+          sha256 = tarballHash;
+        };
+    in
+    (import pinnedPkgs { }).pkgs.postgresql_9_6;
+
+  # PostgreSQL 10 was removed from Nixpkgs with
+  # https://github.com/NixOS/nixpkgs/commit/aa1483114bb329fee7e1266100b8d8921ed4723f
+  # We pin its parent commit to get the last version that was available.
+  postgresql_10 =
+    let
+      rev = "79661ba7e2fb96ebefbb537458a5bbae9dc5bd1a";
+      tarballHash = "0rn796pfn4sg90ai9fdnwmr10a2s835p1arazzgz46h6s5cxvq97";
+      pinnedPkgs =
+        builtins.fetchTarball {
+          url = "https://github.com/nixos/nixpkgs/archive/${rev}.tar.gz";
+          sha256 = tarballHash;
+        };
+    in
+    (import pinnedPkgs { }).pkgs.postgresql_10;
 }
@@ -18,7 +18,12 @@
        done
      '';

-  # See: https://github.com/NixOS/nixpkgs/pull/87879
-  nixpkgs-openssl-split-runtime-dependencies-of-static-builds =
-    ./nixpkgs-openssl-split-runtime-dependencies-of-static-builds.patch;
+  static-haskell-nix-ncurses =
+    ./static-haskell-nix-ncurses.patch;
+  static-haskell-nix-ghc-bignum =
+    ./static-haskell-nix-ghc-bignum.patch;
+  static-haskell-nix-openssl =
+    ./static-haskell-nix-openssl.patch;
+  postgresql-atexit =
+    ./postgresql-atexit.patch;
 }
@@ -1,76 +0,0 @@
-diff --git a/pkgs/development/libraries/openssl/default.nix b/pkgs/development/libraries/openssl/default.nix
-index d4be8cc2428..3979698711f 100644
--- a/pkgs/development/libraries/openssl/default.nix
-+++ b/pkgs/development/libraries/openssl/default.nix
-@@ -50,9 +50,21 @@ let
-       substituteInPlace crypto/async/arch/async_posix.h \
-         --replace '!defined(__ANDROID__) && !defined(__OpenBSD__)' \
-                   '!defined(__ANDROID__) && !defined(__OpenBSD__) && 0'
-+    '' + optionalString static
-+    # On static builds, the ENGINESDIR will be empty, but its path will be
-+    # compiled into the library. In order to minimize the runtime dependencies
-+    # of packages that statically link openssl, we move it into the OPENSSLDIR,
-+    # which will be separated into the 'etc' output.
-+    ''
-+      substituteInPlace Configurations/unix-Makefile.tmpl \
-+        --replace 'ENGINESDIR=$(libdir)/engines-{- $sover_dirname -}' \
-+                  'ENGINESDIR=$(OPENSSLDIR)/engines-{- $sover_dirname -}'
-     '';
- 
-    outputs = [ "bin" "dev" "out" "man" ] ++ optional withDocs "doc";
-+    outputs = [ "bin" "dev" "out" "man" ]
-+      ++ optional withDocs "doc"
-+      # Separate output for the runtime dependencies of the static build.
-+      ++ optional static "etc";
-     setOutputFlags = false;
-     separateDebugInfo =
-       !stdenv.hostPlatform.isDarwin &&
-@@ -101,7 +113,17 @@ let
-     configureFlags = [
-       "shared" # "shared" builds both shared and static libraries
-       "--libdir=lib"
-      "--openssldir=etc/ssl"
-+      (if !static then
-+         "--openssldir=etc/ssl"
-+       else
-+         # Separate the OPENSSLDIR into its own output, as its path will be
-+         # compiled into 'libcrypto.a'. This makes it a runtime dependency of
-+         # any package that statically links openssl, so we want to keep that
-+         # output minimal. We need to prepend '/.' to the path in order to make
-+         # it appear absolute before variable expansion, the 'prefix' would be
-+         # prepended to it otherwise.
-+         "--openssldir=/.$(etc)/etc/ssl"
-+      )
-     ] ++ lib.optionals withCryptodev [
-       "-DHAVE_CRYPTODEV"
-       "-DUSE_CRYPTODEV_DIGESTS"
-@@ -131,6 +153,9 @@ let
-       if [ -n "$(echo $out/lib/*.so $out/lib/*.dylib $out/lib/*.dll)" ]; then
-           rm "$out/lib/"*.a
-       fi
-+
-+      # 'etc' is a separate output on static builds only.
-+      etc=$out
-     '' + lib.optionalString (!stdenv.hostPlatform.isWindows)
-       # Fix bin/c_rehash's perl interpreter line
-       #
-@@ -152,14 +177,15 @@ let
-       mv $out/include $dev/
- 
-       # remove dependency on Perl at runtime
-      rm -r $out/etc/ssl/misc
-+      rm -r $etc/etc/ssl/misc
- 
-      rmdir $out/etc/ssl/{certs,private}
-+      rmdir $etc/etc/ssl/{certs,private}
-     '';
- 
-     postFixup = lib.optionalString (!stdenv.hostPlatform.isWindows) ''
-      # Check to make sure the main output doesn't depend on perl
-      if grep -r '${buildPackages.perl}' $out; then
-+      # Check to make sure the main output and the static runtime dependencies
-+      # don't depend on perl
-+      if grep -r '${buildPackages.perl}' $out $etc; then
-         echo "Found an erroneous dependency on perl ^^^" >&2
-         exit 1
-       fi
@@ -0,0 +1,11 @@
+--- a/src/interfaces/libpq/Makefile
+++ b/src/interfaces/libpq/Makefile
+@@ -118,7 +118,7 @@ backend_src = $(top_srcdir)/src/backend
+ libpq-refs-stamp: $(shlib)
+ ifneq ($(enable_coverage), yes)
+ ifeq (,$(filter aix solaris,$(PORTNAME)))
+-	@if nm -A -u $< 2>/dev/null | grep -v __cxa_atexit | grep exit; then \
+	@if nm -A -u $< 2>/dev/null | grep " exit"; then \
+ 		echo 'libpq must not be calling any function which invokes exit'; exit 1; \
+ 	fi
+ endif
@@ -0,0 +1,12 @@
+diff --git a/survey/default.nix b/survey/default.nix
+index 70afbbc..28cb0e9 100644
+--- a/survey/default.nix
+++ b/survey/default.nix
+@@ -81,6 +81,7 @@ let
+   # `.override` and the likes).
+   isProperHaskellPackage = val:
+     lib.isDerivation val && # must pass lib.isDerivation
+    val.pname != "ghc-bignum" &&
+     val ? env; # must have an .env key
+ 
+   # Function that tells us if a given Haskell package has an executable.
@@ -0,0 +1,13 @@
+diff --git a/survey/default.nix b/survey/default.nix
+index 46d8066..a47f214 100644
+--- a/survey/default.nix
+++ b/survey/default.nix
+@@ -1519,7 +1519,7 @@ let
+                   [
+                     "--enable-executable-static" # requires `useFixedCabal`
+                     # `enableShared` seems to be required to avoid `recompile with -fPIC` errors on some packages.
+-                    "--extra-lib-dirs=${final.ncurses.override { enableStatic = true; enableShared = true; }}/lib"
+                    "--extra-lib-dirs=${final.ncurses.override { enableStatic = true; }}/lib"
+                   ]
+                   # TODO Figure out why this and the below libffi are necessary.
+                   #      `working` and `workingStackageExecutables` don't seem to need that,
@@ -0,0 +1,12 @@
+diff --git a/survey/default.nix b/survey/default.nix
+index cf1bd31..9d34753 100644
+--- a/survey/default.nix
+++ b/survey/default.nix
+@@ -736,6 +736,7 @@ let
+     openblas = previous.openblas.override { enableStatic = true; };
+ 
+     openssl = previous.openssl.override { static = true; };
+    openssl_1_1 = previous.openssl_1_1.override { static = true; };
+ 
+     libsass = previous.libsass.overrideAttrs (old: { dontDisableStatic = true; });
+ 
@@ -1,5 +1,5 @@
 # Derive a fully static Haskell package based on musl instead of glibc.
-{ nixpkgs, compiler, patches, allOverlays }:
+{ nixpkgs, system, compiler, patches, allOverlays }:

 name: src:
 let
@@ -17,14 +17,9 @@ let
    patches.applyPatches "patched-static-haskell-nix"
      static-haskell-nix
      [
-        # No patches currently required.
-      ];
-
-  patchedNixpkgs =
-    patches.applyPatches "patched-nixpkgs"
-      nixpkgs
-      [
-        patches.nixpkgs-openssl-split-runtime-dependencies-of-static-builds
+        patches.static-haskell-nix-ncurses
+        patches.static-haskell-nix-ghc-bignum
+        patches.static-haskell-nix-openssl
      ];

  extraOverrides =
@@ -40,7 +35,7 @@ let
  overlays =
    [
      allOverlays.postgresql-future
-      allOverlays.postgresql-default
+      (allOverlays.postgresql-default { inherit patches; })
      (allOverlays.haskell-packages { inherit compiler extraOverrides; })
      # Disable failing tests for postgresql on musl that should have no impact
      # on the libpq that we need (collate.icu.utf8 and foreign regression
@@ -50,13 +45,13 @@ let
      )
    ];

-  # Apply our overlay to the given pkgs.
+  # Apply our overlay to nixpkgs.
  normalPkgs =
-    import patchedNixpkgs { inherit overlays; };
+    import nixpkgs { inherit overlays system; };

  defaultCabalPackageVersionComingWithGhc =
    {
-      ghc8107 = "Cabal_3_2_1_0";
+      ghc924 = "Cabal_3_6_3_0";
    }."${compiler}";

  # The static-haskell-nix 'survey' derives a full static set of Haskell
@@ -28,6 +28,8 @@ let
      ''
        # clean old coverage data, too
        rm -rf .hpc coverage
+        # clean old hie files
+        find . -name "*.hie" -type f -delete
        exec ${cabal-install}/bin/cabal v2-clean
      '';

@@ -4,7 +4,10 @@
 , checkedShellScript
 , devCabalOptions
 , entr
+, git
+, gnugrep
 , graphviz
+, haskellPackages
 , hsie
 , nix
 , silver-searcher
@@ -29,7 +32,7 @@ let
            "ARG_POSITIONAL_SINGLE([command], [Command to run])"
            "ARG_LEFTOVERS([command arguments])"
          ];
-        addCommandCompletion = true;
+        positionalCompletion = "_command";
        redirectTixFiles = false; # will be done by sub-command
        inRootDir = true;
      }
@@ -64,23 +67,172 @@ let
        name = "postgrest-check";
        docs =
          ''
-            Run most checks that will also run on CI.
+            Run most checks that will also run on CI, but only against the
+            latest PostgreSQL version.

-            This currently excludes the memory tests, as those are particularly
-            expensive.
+            This currently excludes the memory and spec-idempotence tests,
+            as those are particularly expensive.
          '';
        inRootDir = true;
      }
      ''
-        ${withTools}/bin/postgrest-with-all ${tests}/bin/postgrest-test-spec
-        ${withTools}/bin/postgrest-with-all ${tests}/bin/postgrest-test-querycost
+        ${tests}/bin/postgrest-test-spec
        ${tests}/bin/postgrest-test-doctests
-        ${tests}/bin/postgrest-test-spec-idempotence
        ${tests}/bin/postgrest-test-io
        ${style}/bin/postgrest-lint
        ${style}/bin/postgrest-style-check
      '';

+  gitHooks =
+    let
+      name = "postgrest-git-hooks";
+    in
+    checkedShellScript
+      {
+        inherit name;
+        docs =
+          ''
+            Enable or disable git pre-commit and pre-push hooks.
+
+            Basic is faster and will only run:
+              - pre-commit: postgrest-style
+              - pre-push: postgrest-lint
+
+            Full takes a lot more time and will run:
+              - pre-commit: postgrest-style && postgrest-lint
+              - pre-push: postgrest-check
+
+            Changes made by postgrest-style will be staged automatically.
+
+            Example usage:
+              postgrest-git-hooks disable
+              postgrest-git-hooks enable basic
+              postgrest-git-hooks enable full
+
+            The "run" operation and "--hook" argument are only used internally.
+          '';
+        args =
+          [
+            "ARG_POSITIONAL_SINGLE([operation], [Operation])"
+            "ARG_TYPE_GROUP_SET([OPERATION], [OPERATION], [operation], [disable,enable,run])"
+            "ARG_POSITIONAL_SINGLE([mode], [Mode], [basic])"
+            "ARG_TYPE_GROUP_SET([MODE], [MODE], [mode], [basic,full])"
+            "ARG_OPTIONAL_SINGLE([hook], , [Hook], [pre-commit])"
+            "ARG_TYPE_GROUP_SET([HOOK], [HOOK], [hook], [pre-commit,pre-push])"
+          ];
+        positionalCompletion =
+          ''
+            if test "$prev" == "${name}"; then
+              COMPREPLY=( $(compgen -W "enable disable" -- "$cur") )
+            elif test "$prev" == "enable" || test "$prev" == "disable"; then
+              COMPREPLY=( $(compgen -W "basic full" -- "$cur") )
+            fi
+          '';
+        inRootDir = true;
+      }
+      ''
+        if [ run != "$_arg_operation" ]; then
+          # Remove all hooks first and ignore failures because the file might be missing.
+          # This assumes that we're only adding lines that include "postgrest-git-hooks"
+          # to the hook file.
+          sed -i -e '/postgrest-git-hooks/d' .git/hooks/pre-{commit,push} 2> /dev/null || true
+
+          if [ disable != "$_arg_operation" ]; then
+            # The nix-shell && + nix-shell || pattern makes sure we can run the hook
+            # in a pure nix-shell, where nix-shell itself is not available, too.
+
+            # The $(nix-shell --run "command -v ...") pattern ensures we only need to enable
+            # the hooks once and still run the latest of our hook scripts, even when we
+            # update them in the repo.
+
+            echo 'command -v nix-shell > /dev/null || postgrest-git-hooks --hook=pre-commit run' "$_arg_mode" \
+              >> .git/hooks/pre-commit
+            # shellcheck disable=SC2016
+            echo 'command -v nix-shell > /dev/null && $(nix-shell --quiet -Q --run "command -v postgrest-git-hooks") --hook=pre-commit run' "$_arg_mode" \
+             >> .git/hooks/pre-commit
+            chmod +x .git/hooks/pre-commit
+
+            echo 'command -v nix-shell > /dev/null || postgrest-git-hooks --hook=pre-push run' "$_arg_mode" \
+              >> .git/hooks/pre-push
+            # shellcheck disable=SC2016
+            echo 'command -v nix-shell > /dev/null && $(nix-shell --quiet -Q --run "command -v postgrest-git-hooks") --hook=pre-push run' "$_arg_mode" \
+             >> .git/hooks/pre-push
+            chmod +x .git/hooks/pre-push
+          fi
+        else
+          # When run from a git hook, the GIT_ environment variables conflict with our withGit helper.
+          # The following unsets all GIT_ variables.
+          unset "''${!GIT_@}"
+
+          # shellcheck disable=SC2317
+          function restore () {
+            ref="$(git stash list --format=format:%gD --grep "$1" -n1)"
+            # this will avoid merge conflicts when applying the stash
+            ${git}/bin/git restore --source="$ref" .
+            # restore untracked files, too. could fail with no files
+            if [ "$(git show --numstat --format=oneline "$ref^3" | wc -l)" -gt 1 ]; then
+              ${git}/bin/git restore --overlay --source="$ref^3" .
+            fi
+            ${git}/bin/git stash drop "$ref"
+          }
+
+          case "$_arg_mode" in
+            basic)
+              case "$_arg_hook" in
+                pre-commit)
+                  # To be able to automatically add only changes from postgrest-style to the staging area,
+                  # we need to run postgrest-style twice. Otherwise we'd risk merge conflicts when popping
+                  # the stash afterwards.
+                  ${style}/bin/postgrest-style
+
+                  stash="postgrest-git-hooks-$RANDOM"
+                  ${git}/bin/git stash push --include-untracked --keep-index -m "$stash"
+                  if [ "$(git stash list --grep $stash)" ]; then
+                    # Only create the stash pop trap, if we actually created a stash.
+                    # Otherwise stash pop will cause havoc.
+                    trap 'restore "$stash"' EXIT
+                  fi
+
+                  ${style}/bin/postgrest-style
+                  ${git}/bin/git add .
+                  ;;
+                pre-push)
+                  # Create a clean working tree without any uncomitted changes.
+                  ${withTools.withGit} HEAD ${style}/bin/postgrest-lint
+                  ;;
+              esac
+              ;;
+            full)
+              case "$_arg_hook" in
+                pre-commit)
+                  # To be able to automatically add only changes from postgrest-style to the staging area,
+                  # we need to run postgrest-style twice. Otherwise we'd risk merge conflicts when popping
+                  # the stash afterwards.
+                  ${style}/bin/postgrest-style
+
+                  stash="postgrest-git-hooks-$RANDOM"
+                  ${git}/bin/git stash push --include-untracked --keep-index -m "$stash"
+                  if [ "$(git stash list --grep $stash)" ]; then
+                    # Only create the stash pop trap, if we actually created a stash.
+                    # Otherwise stash pop will cause havoc.
+                    trap 'restore "$stash"' EXIT
+                  fi
+
+                  ${style}/bin/postgrest-style
+                  ${git}/bin/git add .
+
+                  ${style}/bin/postgrest-lint
+                  ;;
+                pre-push)
+                  # Create a clean working tree without any uncomitted changes.
+                  ${withTools.withGit} HEAD ${check}
+                  ;;
+              esac
+              ;;
+          esac
+        fi
+      '';
+
  dumpMinimalImports =
    checkedShellScript
      {
@@ -146,6 +298,7 @@ buildToolbox
    watch
    pushCachix
    check
+    gitHooks
    dumpMinimalImports
    hsieMinimalImports
    hsieGraphModules
@@ -93,3 +93,18 @@ Image efficiency score: 100 %

 Count   Total Space  Path
 ```
+
+# Deriving from the optimized image
+
+Since the docker image is minimal, it does not contain a shell or other utilities.
+To derive a non-minimal image, you can do the following:
+
+```Dockerfile
+# derive from any base image you want
+FROM alpine:latest
+
+# copy PostgREST over
+COPY --from=postgrest/postgrest /bin/postgrest /bin
+
+# add your other stuff
+```
@@ -8,7 +8,7 @@ let
    dockerTools.buildImage {
      name = "postgrest";
      tag = "latest";
-      contents = postgrest;
+      copyToRoot = postgrest;

      # Set the current time as the image creation date. This makes the build
      # non-reproducible, but that should not be an issue for us.
@@ -0,0 +1,178 @@
+{ buildToolbox
+, checkedShellScript
+, jq
+, python3Packages
+, vegeta
+, withTools
+, writers
+}:
+let
+  runner =
+    checkedShellScript
+      {
+        name = "postgrest-loadtest-runner";
+        docs = "Run vegeta. Assume PostgREST to be running.";
+        args = [
+          "ARG_LEFTOVERS([additional vegeta arguments])"
+          "ARG_USE_ENV([PGRST_SERVER_UNIX_SOCKET], [], [Unix socket to connect to running PostgREST instance])"
+        ];
+      }
+      ''
+        # ARG_USE_ENV only adds defaults or docs for environment variables
+        # We manually implement a required check here
+        # See also: https://github.com/matejak/argbash/issues/80
+        : "''${PGRST_SERVER_UNIX_SOCKET:?PGRST_SERVER_UNIX_SOCKET is required}"
+
+        ${vegeta}/bin/vegeta -cpus 1 attack \
+                                     -unix-socket "$PGRST_SERVER_UNIX_SOCKET" \
+                                     -max-workers 1 \
+                                     -workers 1 \
+                                     -rate 0 \
+                                     -duration 60s \
+                                     "''${_arg_leftovers[@]}"
+      '';
+
+  loadtest =
+    checkedShellScript
+      {
+        name = "postgrest-loadtest";
+        docs = "Run the vegeta loadtests with PostgREST.";
+        args = [
+          "ARG_OPTIONAL_SINGLE([output], [o], [Filename to dump json output to], [./loadtest/result.bin])"
+          "ARG_OPTIONAL_SINGLE([testdir], [t], [Directory to load tests and fixtures from], [./test/load])"
+          "ARG_LEFTOVERS([additional vegeta arguments])"
+        ];
+        inRootDir = true;
+      }
+      ''
+        # previously required settings to make this work with older branches
+        export PGRST_DB_ANON_ROLE="postgrest_test_anonymous"
+        export PGRST_DB_URI="postgresql://"
+        export PGRST_DB_SCHEMAS="test"
+
+        export PGRST_DB_CONFIG="false"
+        export PGRST_DB_POOL="1"
+        export PGRST_DB_TX_END="rollback-allow-override"
+        export PGRST_LOG_LEVEL="crit"
+
+        mkdir -p "$(dirname "$_arg_output")"
+
+        # shellcheck disable=SC2145
+        ${withTools.withPg} --fixtures "$_arg_testdir"/fixtures.sql \
+        ${withTools.withPgrst} \
+        sh -c "cd \"$_arg_testdir\" && ${runner} -targets targets.http -output \"$_arg_output\" \"''${_arg_leftovers[@]}\""
+        ${vegeta}/bin/vegeta report -type=text "$_arg_output"
+      '';
+
+  loadtestAgainst =
+    let
+      name = "postgrest-loadtest-against";
+    in
+    checkedShellScript
+      {
+        inherit name;
+        docs =
+          ''
+            Run the vegeta loadtest twice:
+            - once on the <target> branch
+            - once in the current worktree
+          '';
+        args = [
+          "ARG_POSITIONAL_SINGLE([target], [Commit-ish reference to compare with])"
+          "ARG_LEFTOVERS([additional vegeta arguments])"
+        ];
+        positionalCompletion =
+          ''
+            if test "$prev" == "${name}"; then
+              __gitcomp_nl "$(__git_refs)"
+            fi
+          '';
+        inRootDir = true;
+      }
+      ''
+        cat << EOF
+
+        Running loadtest on "$_arg_target"...
+
+        EOF
+
+        # Runs the test files from the current working tree
+        # to make sure both tests are run with the same files.
+        # Save the results in the current working tree, too,
+        # otherwise they'd be lost in the temporary working tree
+        # created by withTools.withGit.
+        ${withTools.withGit} "$_arg_target" ${loadtest} --output "$PWD/loadtest/$_arg_target.bin" --testdir "$PWD/test/load" "''${_arg_leftovers[@]}"
+
+        cat << EOF
+
+        Done running on "$_arg_target".
+
+        EOF
+
+        cat << EOF
+
+        Running loadtest on HEAD...
+
+        EOF
+
+        ${loadtest} --output "$PWD/loadtest/head.bin" --testdir "$PWD/test/load" "''${_arg_leftovers[@]}"
+
+        cat << EOF
+
+        Done running on HEAD.
+
+        EOF
+      '';
+
+  reporter =
+    checkedShellScript
+      {
+        name = "postgrest-loadtest-reporter";
+        docs = "Create a named json report for a single result file.";
+        args = [
+          "ARG_POSITIONAL_SINGLE([file], [Filename of result to create report for])"
+          "ARG_LEFTOVERS([additional vegeta arguments])"
+        ];
+        inRootDir = true;
+      }
+      ''
+        ${vegeta}/bin/vegeta report -type=json "$_arg_file" \
+          | ${jq}/bin/jq --arg branch "$(basename "$_arg_file" .bin)" '. + {branch: $branch}'
+      '';
+
+  toMarkdown =
+    writers.writePython3 "postgrest-loadtest-to-markdown"
+      {
+        libraries = [ python3Packages.pandas python3Packages.tabulate ];
+      }
+      ''
+        import sys
+        import pandas as pd
+
+        pd.read_json(sys.stdin) \
+          .set_index('param') \
+          .drop(['branch', 'earliest', 'end', 'latest']) \
+          .convert_dtypes() \
+          .to_markdown(sys.stdout, floatfmt='.0f')
+      '';
+
+
+  report =
+    checkedShellScript
+      {
+        name = "postgrest-loadtest-report";
+        docs = "Create a report of all loadtest reports as markdown.";
+        inRootDir = true;
+      }
+      ''
+        find loadtest -type f -iname '*.bin' -exec ${reporter} {} \; \
+          | ${jq}/bin/jq '[leaf_paths as $path | {param: $path | join("."), (.branch): getpath($path)}]' \
+          | ${jq}/bin/jq --slurp 'flatten | group_by(.param) | map(add)' \
+          | ${toMarkdown}
+      '';
+
+in
+buildToolbox {
+  name = "postgrest-loadtest";
+  tools = [ loadtest loadtestAgainst report ];
+}
@@ -17,7 +17,7 @@ let
        withPath = [ postgrestProfiled curl ];
      }
      ''
-        ${withTools.latest} test/memory-tests.sh
+        ${withTools.withPg} test/memory/memory-tests.sh
      '';

 in
@@ -1,5 +1,6 @@
 { buildToolbox
 , checkedShellScript
+, coreutils
 , curl
 , jq
 , nix
@@ -33,7 +34,7 @@ let
        commitHash="$(${curl}/bin/curl "${refUrl}" -H "${githubV3Header}" | ${jq}/bin/jq -r .object.sha)"
        tarballUrl="${tarballUrlBase}$commitHash.tar.gz"
        tarballHash="$(${nix}/bin/nix-prefetch-url --unpack "$tarballUrl")"
-        currentDate="$(date --iso)"
+        currentDate="$(${coreutils}/bin/date --iso)"

        cat > nix/nixpkgs-version.nix << EOF
        # Pinned version of Nixpkgs, generated with ${name}.
@@ -40,15 +40,97 @@ let
        )"

        repo_url="https://hub.docker.com/v2/repositories/$DOCKER_REPO/postgrest/"
-        echo "Patching both descriptions at $repo_url ..." 
+        echo "Patching both descriptions at $repo_url ..."
        ${curl}/bin/curl --fail -X PATCH "$repo_url" \
          -H "Authorization: JWT $token" \
          --data-urlencode description@${description} \
          --data-urlencode full_description@${fullDescription}
      '';
+
+  release =
+    checkedShellScript
+      {
+        name = "postgrest-release";
+        docs = "Patch postgrest.cabal, CHANGELOG.md, tag and push all in one go.";
+        args = [ "ARG_POSITIONAL_SINGLE([version], [Version to release], [pre])" ];
+        inRootDir = true;
+      }
+      ''
+        trap "echo You need to be on the main branch to proceed. Exiting ..." ERR
+        [ "$(git rev-parse --abbrev-ref HEAD)" == "main" ]
+        trap "" ERR
+
+        trap "echo You have uncommitted changes in postgrest.cabal. Exiting ..." ERR
+        git diff --exit-code HEAD postgrest.cabal > /dev/null
+        trap "" ERR
+
+        current_version="$(grep -oP '^version:\s*\K.*' postgrest.cabal)"
+        # shellcheck disable=SC2034
+        IFS=. read -r major minor patch pre <<< "$current_version"
+        echo "Current version is $current_version"
+
+        today_date="$(date '+%Y%m%d')"
+        today_date_for_changelog="$(date '+%Y-%m-%d')"
+        bump_pre="$major.$minor.$patch.$today_date"
+        bump_patch="$major.$minor.$((patch+1))"
+        bump_minor="$major.$((minor+1)).0"
+        bump_major="$((major+1)).0.0"
+
+        PS3="Please select the new version: "
+        select new_version in "$bump_pre" "$bump_patch" "$bump_minor" "$bump_major"; do
+          case "$REPLY" in
+            1|2|3|4)
+              echo "Selected $new_version"
+              break
+              ;;
+            *)
+            echo "Invalid option $REPLY"
+            ;;
+          esac
+        done
+
+        echo "Updating postgrest.cabal ..."
+        sed -i -E "s/^(version:\s+).*$/\1$new_version/" postgrest.cabal > /dev/null
+
+        echo "Committing ..."
+        git add postgrest.cabal > /dev/null
+
+        if [[ "$new_version" != "$bump_pre" ]]; then
+          echo "Updating CHANGELOG.md ..."
+          sed -i -E "s/Unreleased/&\n\n## [$new_version] - $today_date_for_changelog/" CHANGELOG.md > /dev/null
+          git add CHANGELOG.md > /dev/null
+        fi
+
+        git commit -m "bump version to $new_version" > /dev/null
+
+        echo "Tagging ..."
+        git tag "v$new_version" > /dev/null
+
+        trap "echo Remote not found. Please push manually ..." ERR
+        remote="$(git remote -v | grep PostgREST/postgrest | grep push | cut -f1)"
+        trap "" ERR
+
+        push="git push --atomic $remote main v$new_version"
+
+        echo "To push both the branch and the new tag, the following will be run:"
+        echo
+        echo "$push"
+        echo
+
+        read -r -p 'Proceed? (y/N) ' REPLY
+        case "$REPLY" in
+          y|Y)
+            $push
+            ;;
+          *)
+            echo "Aborting ..."
+            ;;
+        esac
+      '';
+
 in
 buildToolbox
 {
  name = "postgrest-release";
-  tools = [ dockerHubDescription ];
+  tools = [ dockerHubDescription release ];
 }
@@ -55,7 +55,7 @@ write from scratch.
 # Usage

 To learn how to use this container, see the [PostgREST Docker
-documentation](https://postgrest.com/en/stable/install.html#docker).
+documentation](https://postgrest.org/en/stable/install.html#docker).

 You can configure the PostgREST image by setting
 [enviroment variables](https://postgrest.org/en/stable/configuration.html).
@@ -66,5 +66,5 @@ The image is built from scratch using
 [Nix](https://nixos.org/nixpkgs/manual/#sec-pkgs-dockerTools) instead of a
 `Dockerfile`, which yields a higly secure and optimized image. This is also why
 no commands are listed in the image history. See the [PostgREST
-respository](https://github.com/PostgREST/postgrest/tree/main/nix/docker) for
+respository](https://github.com/PostgREST/postgrest/tree/main/nix/tools/docker) for
 details on the build process and how to inspect the image.
@@ -44,7 +44,9 @@ let
      ''
        ${style}

-        ${git}/bin/git diff-index --exit-code HEAD -- '*.hs' '*.lhs' '*.nix'
+        trap "echo postgrest-style-check failed. Run postgrest-style to fix issues automatically." ERR
+
+        ${git}/bin/git diff-index --exit-code HEAD -- '*.hs' '*.lhs' '*.nix' '*.py'
      '';

  lint =
@@ -67,8 +69,7 @@ let
        echo "Linting bash scripts..."
        ${shellcheck}/bin/shellcheck \
          .github/get_cirrusci_freebsd \
-          .github/release \
-          test/with_tmp_db
+          .github/release

        echo "Linting workflows..."
        ${actionlint}/bin/actionlint
@@ -3,14 +3,17 @@
 , checkedShellScript
 , devCabalOptions
 , ghc
-, glibcLocales
+, glibcLocales ? null
 , gnugrep
-, haskell
 , hpc-codecov
+, hostPlatform
 , jq
+, lib
 , postgrest
 , python3
 , runtimeShell
+, stdenv
+, weeder
 , withTools
 , yq
 }:
@@ -19,24 +22,14 @@ let
    checkedShellScript
      {
        name = "postgrest-test-spec";
-        docs = "Run the Haskell test suite";
+        docs = "Run the Haskell test suite. Use --match PATTERN for running individual specs";
+        args = [ "ARG_LEFTOVERS([hspec arguments])" ];
        inRootDir = true;
        withEnv = postgrest.env;
      }
      ''
-        ${withTools.latest} ${cabal-install}/bin/cabal v2-run ${devCabalOptions} test:spec
-      '';
-
-  testQuerycost =
-    checkedShellScript
-      {
-        name = "postgrest-test-querycost";
-        docs = "Run the Haskell test suite for query costs";
-        inRootDir = true;
-        withEnv = postgrest.env;
-      }
-      ''
-        ${withTools.latest} ${cabal-install}/bin/cabal v2-run ${devCabalOptions} test:querycost
+        ${withTools.withPg} ${cabal-install}/bin/cabal v2-run ${devCabalOptions} \
+          test:spec -- "''${_arg_leftovers[@]}"
      '';

  testDoctests =
@@ -66,7 +59,7 @@ let
        withEnv = postgrest.env;
      }
      ''
-        ${withTools.latest} ${runtimeShell} -c " \
+        ${withTools.withPg} ${runtimeShell} -c " \
          ${cabal-install}/bin/cabal v2-run ${devCabalOptions} test:spec && \
          ${cabal-install}/bin/cabal v2-run ${devCabalOptions} test:spec"
      '';
@@ -75,7 +68,7 @@ let
    python3.withPackages (ps: [
      ps.pyjwt
      ps.pytest
-      ps.pytest_xdist
+      ps.pytest-xdist
      ps.pyyaml
      ps.requests
      ps.requests-unixsocket
@@ -85,28 +78,28 @@ let
    checkedShellScript
      {
        name = "postgrest-test-io";
-        docs = "Run the pytest-based IO tests.";
+        docs = "Run the pytest-based IO tests. Add -k to run tests that match a given expression.";
        args = [ "ARG_LEFTOVERS([pytest arguments])" ];
        inRootDir = true;
        withEnv = postgrest.env;
      }
      ''
        ${cabal-install}/bin/cabal v2-build ${devCabalOptions}
-        ${cabal-install}/bin/cabal v2-exec ${withTools.latest} \
-          ${ioTestPython}/bin/pytest -- -v test/io-tests "''${_arg_leftovers[@]}"
+        ${cabal-install}/bin/cabal v2-exec -- ${withTools.withPg} -f test/io/fixtures.sql \
+          ${ioTestPython}/bin/pytest -v test/io "''${_arg_leftovers[@]}"
      '';

  dumpSchema =
    checkedShellScript
      {
        name = "postgrest-dump-schema";
-        docs = "Dump the loaded schema's DbStructure as a yaml file.";
+        docs = "Dump the loaded schema's SchemaCache as a yaml file.";
        inRootDir = true;
        withEnv = postgrest.env;
        withPath = [ jq ];
      }
      ''
-        ${withTools.latest} \
+        ${withTools.withPg} \
            ${cabal-install}/bin/cabal v2-run ${devCabalOptions} --verbose=0 -- \
            postgrest --dump-schema \
            | ${yq}/bin/yq -y .
@@ -116,69 +109,76 @@ let
    checkedShellScript
      {
        name = "postgrest-coverage";
-        docs = "Run spec and io tests while collecting hpc coverage data.";
+        docs = "Run spec and io tests while collecting hpc coverage data. First runs weeder to detect dead code.";
        args = [ "ARG_LEFTOVERS([hpc report arguments])" ];
        inRootDir = true;
        redirectTixFiles = false;
        withEnv = postgrest.env;
        withTmpDir = true;
      }
-      ''
-        export LOCALE_ARCHIVE="${glibcLocales}/lib/locale/locale-archive"
+      (
+        # required for `hpc markup` in CI; glibcLocales is not available e.g. on Darwin
+        lib.optionalString (stdenv.isLinux && hostPlatform.libc == "glibc") ''
+          export LOCALE_ARCHIVE="${glibcLocales}/lib/locale/locale-archive"
+        '' +

-        # clean up previous coverage reports
-        mkdir -p coverage
-        rm -rf coverage/*
+        ''
+          # clean up previous coverage reports
+          mkdir -p coverage
+          rm -rf coverage/*

-        # build once before running all the tests
-        ${cabal-install}/bin/cabal v2-build ${devCabalOptions} exe:postgrest lib:postgrest test:spec test:querycost
+          # build once before running all the tests
+          ${cabal-install}/bin/cabal v2-build ${devCabalOptions} exe:postgrest lib:postgrest test:spec

-        # collect all tests
-        HPCTIXFILE="$tmpdir"/io.tix \
-          ${withTools.latest} ${cabal-install}/bin/cabal v2-exec ${devCabalOptions} \
-          ${ioTestPython}/bin/pytest -- -v test/io-tests
-          
-        HPCTIXFILE="$tmpdir"/spec.tix \
-          ${withTools.latest} ${cabal-install}/bin/cabal v2-run ${devCabalOptions} test:spec
+          (
+            trap 'echo Found dead code: Check file list above.' ERR ;
+            ${weeder}/bin/weeder --config=./test/weeder.dhall
+          )

-        HPCTIXFILE="$tmpdir"/querycost.tix \
-          ${withTools.latest} ${cabal-install}/bin/cabal v2-run ${devCabalOptions} test:querycost
+          # collect all tests
+          HPCTIXFILE="$tmpdir"/io.tix \
+            ${withTools.withPg} -f test/io/fixtures.sql ${cabal-install}/bin/cabal v2-exec ${devCabalOptions} -- \
+            ${ioTestPython}/bin/pytest -v test/io

-        # Note: No coverage for doctests, as doctests leverage GHCi and GHCi does not support hpc
+          HPCTIXFILE="$tmpdir"/spec.tix \
+            ${withTools.withPg} ${cabal-install}/bin/cabal v2-run ${devCabalOptions} test:spec

-        # collect all the tix files
-        ${ghc}/bin/hpc sum  --union --exclude=Paths_postgrest --output="$tmpdir"/tests.tix \
-          "$tmpdir"/io*.tix "$tmpdir"/spec.tix "$tmpdir"/querycost.tix
+          # Note: No coverage for doctests, as doctests leverage GHCi and GHCi does not support hpc

-        # prepare the overlay
-        ${ghc}/bin/hpc overlay --output="$tmpdir"/overlay.tix test/coverage.overlay
-        ${ghc}/bin/hpc sum --union --output="$tmpdir"/tests-overlay.tix "$tmpdir"/tests.tix "$tmpdir"/overlay.tix
+          # collect all the tix files
+          ${ghc}/bin/hpc sum  --union --exclude=Paths_postgrest --output="$tmpdir"/tests.tix \
+            "$tmpdir"/io*.tix "$tmpdir"/spec.tix

-        # check nothing in the overlay is actually tested
-        ${ghc}/bin/hpc map --function=inv --output="$tmpdir"/inverted.tix "$tmpdir"/tests.tix
-        ${ghc}/bin/hpc combine --function=sub \
-          --output="$tmpdir"/check.tix "$tmpdir"/overlay.tix "$tmpdir"/inverted.tix
-        # returns zero exit code if any count="<non-zero>" lines are found, i.e.
-        # something is covered by both the overlay and the tests
-        if ${ghc}/bin/hpc report --xml "$tmpdir"/check.tix | ${gnugrep}/bin/grep -qP 'count="[^0]'
-        then
-          ${ghc}/bin/hpc markup --highlight-covered --destdir=coverage/overlay "$tmpdir"/overlay.tix || true
-          ${ghc}/bin/hpc markup --highlight-covered --destdir=coverage/check "$tmpdir"/check.tix || true
-          echo "ERROR: Something is covered by both the tests and the overlay:"
-          echo "file://$(pwd)/coverage/check/hpc_index.html"
-          exit 1
-        else
-          # copy the result .tix file to the coverage/ dir to make it available to postgrest-coverage-draft-overlay, too
-          cp "$tmpdir"/tests-overlay.tix coverage/postgrest.tix
-          # prepare codecov json report
-          ${hpc-codecov}/bin/hpc-codecov --mix=.hpc --out=coverage/codecov.json coverage/postgrest.tix
+          # prepare the overlay
+          ${ghc}/bin/hpc overlay --output="$tmpdir"/overlay.tix test/coverage.overlay
+          ${ghc}/bin/hpc sum --union --output="$tmpdir"/tests-overlay.tix "$tmpdir"/tests.tix "$tmpdir"/overlay.tix

-          # create html and stdout reports
-          ${ghc}/bin/hpc markup --destdir=coverage coverage/postgrest.tix
-          echo "file://$(pwd)/coverage/hpc_index.html"
-          ${ghc}/bin/hpc report coverage/postgrest.tix "''${_arg_leftovers[@]}"
-        fi
-      '';
+          # check nothing in the overlay is actually tested
+          ${ghc}/bin/hpc map --function=inv --output="$tmpdir"/inverted.tix "$tmpdir"/tests.tix
+          ${ghc}/bin/hpc combine --function=sub \
+            --output="$tmpdir"/check.tix "$tmpdir"/overlay.tix "$tmpdir"/inverted.tix
+          # returns zero exit code if any count="<non-zero>" lines are found, i.e.
+          # something is covered by both the overlay and the tests
+          if ${ghc}/bin/hpc report --xml "$tmpdir"/check.tix | ${gnugrep}/bin/grep -qP 'count="[^0]'
+          then
+            ${ghc}/bin/hpc markup --highlight-covered --destdir=coverage/overlay "$tmpdir"/overlay.tix || true
+            ${ghc}/bin/hpc markup --highlight-covered --destdir=coverage/check "$tmpdir"/check.tix || true
+            echo "ERROR: Something is covered by both the tests and the overlay:"
+            echo "file://$(pwd)/coverage/check/hpc_index.html"
+            exit 1
+          else
+            # copy the result .tix file to the coverage/ dir to make it available to postgrest-coverage-draft-overlay, too
+            cp "$tmpdir"/tests-overlay.tix coverage/postgrest.tix
+            # prepare codecov json report
+            ${hpc-codecov}/bin/hpc-codecov --mix=.hpc --out=coverage/codecov.json coverage/postgrest.tix
+
+            # create html and stdout reports
+            ${ghc}/bin/hpc markup --destdir=coverage coverage/postgrest.tix
+            echo "file://$(pwd)/coverage/hpc_index.html"
+            ${ghc}/bin/hpc report coverage/postgrest.tix "''${_arg_leftovers[@]}"
+          fi
+        ''
+      );

  coverageDraftOverlay =
    checkedShellScript
@@ -192,6 +192,26 @@ let
        sed -i 's|^module \(.*\):|module \1/|g' test/coverage.overlay
      '';

+  checkStatic =
+    checkedShellScript
+      {
+        name = "postgrest-check-static";
+        docs = "Verify that the argument is a static executable.";
+        args = [ "ARG_POSITIONAL_SINGLE([executable], [Executable])" ];
+        inRootDir = true;
+        withEnv = postgrest.env;
+      }
+      ''
+        exe="$_arg_executable"
+        ldd_output=$(ldd "$exe" 2>&1 || true)
+        if ! grep -q "not a dynamic executable" <<< "$ldd_output"; then
+          echo "not a static executable, ldd output:"
+          echo "$ldd_output"
+          exit 1
+        fi
+        "$exe" --help
+      '';
+
 in
 buildToolbox
 {
@@ -199,12 +219,12 @@ buildToolbox
  tools =
    [
      testSpec
-      testQuerycost
      testDoctests
      testSpecIdempotence
      testIO
      dumpSchema
      coverage
      coverageDraftOverlay
+      checkStatic
    ];
 }
@@ -1,9 +1,14 @@
-{ bashCompletion
+{ bash-completion
 , buildToolbox
+, cabal-install
 , checkedShellScript
+, curl
+, devCabalOptions
+, git
 , lib
 , postgresqlVersions
-, writeTextFile
+, postgrest
+, writeText
 }:
 let
  withTmpDb =
@@ -14,15 +19,14 @@ let
        docs = "Run the given command in a temporary database with ${name}";
        args =
          [
-            "ARG_OPTIONAL_SINGLE([fixtures], [f], [SQL file to load fixtures from], [test/fixtures/load.sql])"
+            "ARG_OPTIONAL_SINGLE([fixtures], [f], [SQL file to load fixtures from], [test/spec/fixtures/load.sql])"
            "ARG_POSITIONAL_SINGLE([command], [Command to run])"
            "ARG_LEFTOVERS([command arguments])"
            "ARG_USE_ENV([PGUSER], [postgrest_test_authenticator], [Authenticator PG role])"
            "ARG_USE_ENV([PGDATABASE], [postgres], [PG database name])"
            "ARG_USE_ENV([PGRST_DB_SCHEMAS], [test], [Schema to expose])"
-            "ARG_USE_ENV([PGRST_DB_ANON_ROLE], [postgrest_test_anonymous], [Anonymous PG role])"
          ];
-        addCommandCompletion = true;
+        positionalCompletion = "_command";
        inRootDir = true;
        redirectTixFiles = false;
        withPath = [ postgresql ];
@@ -30,8 +34,8 @@ let
      }
      ''
        # avoid starting multiple layers of withTmpDb
-        if test -v PGRST_DB_URI; then
-          exec "$@"
+        if test -v PGHOST; then
+          exec "$_arg_command" "''${_arg_leftovers[@]}"
        fi

        setuplog="$tmpdir/setup.log"
@@ -48,9 +52,11 @@ let
        export PGHOST="$tmpdir/socket"
        export PGUSER
        export PGDATABASE
-        export PGRST_DB_URI="postgresql:///$PGDATABASE?host=$PGHOST&user=$PGUSER"
        export PGRST_DB_SCHEMAS
-        export PGRST_DB_ANON_ROLE
+
+        HBA_FILE="$tmpdir/pg_hba.conf"
+        echo "local $PGDATABASE some_protected_user password" > "$HBA_FILE"
+        echo "local $PGDATABASE all trust" >> "$HBA_FILE"

        log "Initializing database cluster..."
        # We try to make the database cluster as independent as possible from the host
@@ -60,9 +66,10 @@ let

        log "Starting the database cluster..."
        # Instead of listening on a local port, we will listen on a unix domain socket.
-        pg_ctl -l "$tmpdir/db.log" -w start -o "-F -c listen_addresses=\"\" -k $PGHOST" \
+        pg_ctl -l "$tmpdir/db.log" -w start -o "-F -c listen_addresses=\"\" -c hba_file=$HBA_FILE -k $PGHOST -c log_statement=\"all\"" \
          >> "$setuplog"

+        # shellcheck disable=SC2317
        stop () {
          log "Stopping the database cluster..."
          pg_ctl stop -m i >> "$setuplog"
@@ -78,27 +85,27 @@ let
      '';

  # Helper script for running a command against all PostgreSQL versions.
-  withAll =
+  withPgAll =
    let
      runners =
        builtins.map
-          (pg:
+          (version:
            ''
              cat << EOF

-              Running against ${pg.name}...
+              Running against ${version.name}...

              EOF

-              trap 'echo "Failed on ${pg.name}"' exit
+              trap 'echo "Failed on ${version.name}"' exit

-              (${withTmpDb pg} "$_arg_command" "''${_arg_leftovers[@]}")
+              (${withTmpDb version} "$_arg_command" "''${_arg_leftovers[@]}")

              trap "" exit

              cat << EOF

-              Done running against ${pg.name}.
+              Done running against ${version.name}.

              EOF
            '')
@@ -113,21 +120,168 @@ let
            "ARG_POSITIONAL_SINGLE([command], [Command to run])"
            "ARG_LEFTOVERS([command arguments])"
          ];
-        addCommandCompletion = true;
+        positionalCompletion = "_command";
        inRootDir = true;
      }
      (lib.concatStringsSep "\n\n" runners);

  # Create a `postgrest-with-postgresql-` for each PostgreSQL version
-  withVersions = builtins.map withTmpDb postgresqlVersions;
+  withPgVersions = builtins.map withTmpDb postgresqlVersions;
+
+  withPg = builtins.head withPgVersions;
+
+  withGit =
+    let
+      name = "postgrest-with-git";
+    in
+    checkedShellScript
+      {
+        inherit name;
+        docs =
+          ''
+            Create a new worktree of the postgrest repo in a temporary directory and
+            check out <commit>, then run <command> with arguments inside the temporary folder.
+          '';
+        args =
+          [
+            "ARG_POSITIONAL_SINGLE([commit], [Commit-ish reference to run command with])"
+            "ARG_POSITIONAL_SINGLE([command], [Command to run])"
+            "ARG_LEFTOVERS([command arguments])"
+          ];
+        positionalCompletion =
+          ''
+            if test "$prev" == "${name}"; then
+              __gitcomp_nl "$(__git_refs)"
+            else
+              _command_offset 2
+            fi
+          '';
+        inRootDir = true;
+      }
+      ''
+        # not using withTmpDir here, because we don't want to keep the directory on error
+        tmpdir="$(mktemp -d)"
+        trap 'rm -rf "$tmpdir"' EXIT
+
+        ${git}/bin/git worktree add -f "$tmpdir" "$_arg_commit" > /dev/null
+
+        cd "$tmpdir"
+        ("$_arg_command" "''${_arg_leftovers[@]}")
+
+        ${git}/bin/git worktree remove -f "$tmpdir" > /dev/null
+      '';
+
+  legacyConfig =
+    writeText "legacy.conf"
+      ''
+        # Using this config file to support older postgrest versions for `postgrest-loadtest-against`
+        db-uri="$(PGRST_DB_URI)"
+        db-schema="$(PGRST_DB_SCHEMAS)"
+        db-anon-role="$(PGRST_DB_ANON_ROLE)"
+        db-pool="$(PGRST_DB_POOL)"
+        server-unix-socket="$(PGRST_SERVER_UNIX_SOCKET)"
+        log-level="$(PGRST_LOG_LEVEL)"
+      '';
+
+  waitForPgrstPid =
+    checkedShellScript
+      {
+        name = "postgrest-wait-for-pgrst-pid";
+        docs = "Wait for PostgREST to be running. Needs to be a separate command for timeout to work below.";
+        args = [
+          "ARG_USE_ENV([PGRST_SERVER_UNIX_SOCKET], [], [Unix socket to check for running PostgREST instance])"
+        ];
+      }
+      ''
+        # ARG_USE_ENV only adds defaults or docs for environment variables
+        # We manually implement a required check here
+        # See also: https://github.com/matejak/argbash/issues/80
+        : "''${PGRST_SERVER_UNIX_SOCKET:?PGRST_SERVER_UNIX_SOCKET is required}"
+
+        until [ -S "$PGRST_SERVER_UNIX_SOCKET" ]
+        do
+          sleep 0.1
+        done
+
+        # return pid of postgrest process
+        lsof -t -c '/^postgrest$/' "$PGRST_SERVER_UNIX_SOCKET"
+      '';
+
+  waitForPgrstReady =
+    checkedShellScript
+      {
+        name = "postgrest-wait-for-pgrst-ready";
+        docs = "Wait for PostgREST to be ready to serve requests. Needs to be a separate command for timeout to work below.";
+        args = [
+          "ARG_USE_ENV([PGRST_SERVER_UNIX_SOCKET], [], [Unix socket to check for running PostgREST instance])"
+        ];
+      }
+      ''
+        # ARG_USE_ENV only adds defaults or docs for environment variables
+        # We manually implement a required check here
+        # See also: https://github.com/matejak/argbash/issues/80
+        : "''${PGRST_SERVER_UNIX_SOCKET:?PGRST_SERVER_UNIX_SOCKET is required}"
+
+        function check_status () {
+          ${curl}/bin/curl -s -o /dev/null -w "%{http_code}" --unix-socket "$PGRST_SERVER_UNIX_SOCKET" http://localhost/
+        }
+
+        while [[ "$(check_status)" != "200" ]];
+           do sleep 0.1;
+        done
+      '';
+
+  withPgrst =
+    checkedShellScript
+      {
+        name = "postgrest-with-pgrst";
+        docs = "Build and run PostgREST and run <command> with PGRST_SERVER_UNIX_SOCKET set.";
+        args =
+          [
+            "ARG_POSITIONAL_SINGLE([command], [Command to run])"
+            "ARG_LEFTOVERS([command arguments])"
+          ];
+        positionalCompletion = "_command";
+        inRootDir = true;
+        withEnv = postgrest.env;
+        withTmpDir = true;
+      }
+      ''
+        export PGRST_SERVER_UNIX_SOCKET="$tmpdir"/postgrest.socket
+
+        rm -f result
+        echo -n "Building postgrest... "
+        nix-build -A postgrestPackage > "$tmpdir"/build.log 2>&1 || {
+          echo "failed, output:"
+          cat "$tmpdir"/build.log
+          exit 1
+        }
+        echo "done."
+
+        echo -n "Starting postgrest... "
+        ./result/bin/postgrest ${legacyConfig} > "$tmpdir"/run.log 2>&1 &
+        pid=$!
+        # shellcheck disable=SC2317
+        cleanup() {
+          kill "$pid" || true
+        }
+        trap cleanup EXIT
+
+        timeout -s TERM 5 ${waitForPgrstReady} || {
+          echo "timed out, output:"
+          cat "$tmpdir"/run.log
+          exit 1
+        }
+        echo "done."
+
+        ("$_arg_command" "''${_arg_leftovers[@]}")
+      '';

 in
 buildToolbox
 {
  name = "postgrest-with";
-  tools = [ withAll ] ++ withVersions;
-  extra = {
-    # make withTools.latest available for other nix files
-    latest = withTmpDb (builtins.head postgresqlVersions);
-  };
+  tools = [ withPgAll withGit withPgrst ] ++ withPgVersions;
+  # make withTools available for other nix files
+  extra = { inherit withGit withPg withPgAll withPgrst; };
 }
@@ -1,8 +1,8 @@
 name:               postgrest
-version:            9.0.0
+version:            10.2.0
 synopsis:           REST API for any Postgres database
 description:        Reads the schema of a PostgreSQL database and creates RESTful routes
-                    for the tables and views, supporting all HTTP verbs that security
+                    for tables, views, and functions, supporting all HTTP methods that security
                    permits.
 license:            MIT
 license-file:       LICENSE
@@ -43,77 +43,86 @@ library
                      PostgREST.Config.JSPath
                      PostgREST.Config.PgVersion
                      PostgREST.Config.Proxy
-                      PostgREST.ContentType
-                      PostgREST.DbStructure
-                      PostgREST.DbStructure.Identifiers
-                      PostgREST.DbStructure.Proc
-                      PostgREST.DbStructure.Relationship
-                      PostgREST.DbStructure.Table
+                      PostgREST.Cors
+                      PostgREST.SchemaCache
+                      PostgREST.SchemaCache.Identifiers
+                      PostgREST.SchemaCache.Proc
+                      PostgREST.SchemaCache.Relationship
+                      PostgREST.SchemaCache.Table
                      PostgREST.Error
-                      PostgREST.GucHeader
-                      PostgREST.Middleware
-                      PostgREST.OpenAPI
+                      PostgREST.Logger
+                      PostgREST.MediaType
+                      PostgREST.Query
                      PostgREST.Query.QueryBuilder
                      PostgREST.Query.SqlFragment
                      PostgREST.Query.Statements
+                      PostgREST.Plan
+                      PostgREST.Plan.CallPlan
+                      PostgREST.Plan.MutatePlan
+                      PostgREST.Plan.ReadPlan
                      PostgREST.RangeQuery
-                      PostgREST.Request.ApiRequest
-                      PostgREST.Request.DbRequestBuilder
-                      PostgREST.Request.Parsers
-                      PostgREST.Request.Preferences
-                      PostgREST.Request.Types
+                      PostgREST.ApiRequest
+                      PostgREST.ApiRequest.Preferences
+                      PostgREST.ApiRequest.QueryParams
+                      PostgREST.ApiRequest.Types
+                      PostgREST.Response
+                      PostgREST.Response.OpenAPI
+                      PostgREST.Response.GucHeader
                      PostgREST.Version
                      PostgREST.Workers
  other-modules:      Paths_postgrest
-  build-depends:      base                      >= 4.9 && < 4.16
-                    , HTTP                      >= 4000.3.7 && < 4000.4
+  build-depends:      base                      >= 4.9 && < 4.17
+                    , HTTP                      >= 4000.3.7 && < 4000.5
                    , Ranged-sets               >= 0.3 && < 0.5
-                    , aeson                     >= 1.4.7 && < 1.6
-                    , ansi-wl-pprint            >= 0.6.7 && < 0.7
+                    , aeson                     >= 2.0.3 && < 2.2
                    , auto-update               >= 0.1.4 && < 0.2
                    , base64-bytestring         >= 1 && < 1.3
-                    , bytestring                >= 0.10.8 && < 0.11
+                    , bytestring                >= 0.10.8 && < 0.12
                    , case-insensitive          >= 1.2 && < 1.3
                    , cassava                   >= 0.4.5 && < 0.6
                    , configurator-pg           >= 0.2 && < 0.3
                    , containers                >= 0.5.7 && < 0.7
-                    , contravariant             >= 1.4 && < 1.6
                    , contravariant-extras      >= 0.3.3 && < 0.4
                    , cookie                    >= 0.4.2 && < 0.5
                    , either                    >= 4.4.1 && < 5.1
-                    , fast-logger               >= 2.4.5
+                    , fuzzyset                  >= 0.2.3
                    , gitrev                    >= 1.2 && < 1.4
-                    , hasql                     >= 1.4 && < 1.5
-                    , hasql-dynamic-statements  == 0.3.1
+                    , hasql                     >= 1.6.1.1 && < 1.7
+                    , hasql-dynamic-statements  >= 0.3.1 && < 0.4
                    , hasql-notifications       >= 0.1 && < 0.3
-                    , hasql-pool                >= 0.5 && < 0.6
+                    , hasql-pool                >= 0.9 && < 0.10
                    , hasql-transaction         >= 1.0.1 && < 1.1
                    , heredoc                   >= 0.2 && < 0.3
                    , http-types                >= 0.12.2 && < 0.13
                    , insert-ordered-containers >= 0.2.2 && < 0.3
                    , interpolatedstring-perl6  >= 1 && < 1.1
-                    , jose                      >= 0.8.1 && < 0.9
-                    , lens                      >= 4.14 && < 5.1
-                    , lens-aeson                >= 1.0.1 && < 1.2
+                    , jose                      >= 0.8.5.1 && < 0.11
+                    , lens                      >= 4.14 && < 5.3
+                    , lens-aeson                >= 1.0.1 && < 1.3
                    , mtl                       >= 2.2.2 && < 2.3
+                    , network                   >= 2.6 && < 3.2
                    , network-uri               >= 2.6.1 && < 2.8
-                    , optparse-applicative      >= 0.13 && < 0.17
+                    , optparse-applicative      >= 0.13 && < 0.18
                    , parsec                    >= 3.1.11 && < 3.2
-                    , protolude                 >= 0.3 && < 0.4
+                    , protolude                 >= 0.3.1 && < 0.4
                    , regex-tdfa                >= 1.2.2 && < 1.4
                    , retry                     >= 0.7.4 && < 0.10
                    , scientific                >= 0.3.4 && < 0.4
-                    , swagger2                  >= 2.4 && < 2.7
+                    , swagger2                  >= 2.4 && < 2.9
                    , text                      >= 1.2.2 && < 1.3
-                    , time                      >= 1.6 && < 1.11
+                    , time                      >= 1.6 && < 1.12
                    , unordered-containers      >= 0.2.8 && < 0.3
-                    , vector                    >= 0.11 && < 0.13
+                    , vault                     >= 0.3.1.5 && < 0.4
+                    , vector                    >= 0.11 && < 0.14
                    , wai                       >= 3.2.1 && < 3.3
                    , wai-cors                  >= 0.2.5 && < 0.3
-                    , wai-extra                 >= 3.0.19 && < 3.2
-                    , wai-logger                >= 2.3.2
-                    , wai-middleware-static     >= 0.8.1 && < 0.10
-                    , warp                      >= 3.2.12 && < 3.4
+                    , wai-extra                 >= 3.1.8 && < 3.2
+                    -- We already depend on wai-logger >= 2.3.7 indirectly via wai-extra,
+                    -- but we want to depend on 2.4.0 which fixes 'unknownSocket' log output
+                    -- for unix sockets; this is tested in test/io/test_io.py. See
+                    -- https://github.com/kazu-yamamoto/logger/commit/3a71ca70afdbb93d4ecf0083eeba1fbbbcab3fc3
+                    , wai-logger                >= 2.4.0
+                    , warp                      >= 3.3.19 && < 3.4
                      -- -fno-spec-constr may help keep compile time memory use in check,
                      --   see https://gitlab.haskell.org/ghc/ghc/issues/16017#note_219304
                      -- -optP-Wno-nonportable-include-path
@@ -123,7 +132,7 @@ library
                      -fno-spec-constr -optP-Wno-nonportable-include-path

  if flag(dev)
-    ghc-options: -O0
+    ghc-options: -O0 -fwrite-ide-info
    if flag(hpc)
      ghc-options: -fhpc -hpcdir .hpc
  else
@@ -133,7 +142,6 @@ library
    build-depends:
      unix
      , directory >= 1.2.6 && < 1.4
-      , network   >= 2.6 && < 3.2
    exposed-modules:
      PostgREST.Unix

@@ -143,16 +151,18 @@ executable postgrest
                      NoImplicitPrelude
  hs-source-dirs:     main
  main-is:            Main.hs
-  build-depends:      base                >= 4.9 && < 4.16
+  build-depends:      base                >= 4.9 && < 4.17
                    , containers          >= 0.5.7 && < 0.7
                    , postgrest
-                    , protolude           >= 0.3 && < 0.4
-  ghc-options:        -threaded -rtsopts "-with-rtsopts=-N -I2"
+                    , protolude           >= 0.3.1 && < 0.4
+  ghc-options:        -threaded -rtsopts "-with-rtsopts=-N -I0 -qg"
                      -O2 -Werror -Wall -fwarn-identities
                      -fno-spec-constr -optP-Wno-nonportable-include-path

  if flag(dev)
-    ghc-options: -O0
+    ghc-options: -O0 -fwrite-ide-info
+                 -- https://github.com/PostgREST/postgrest/issues/387
+                 -with-rtsopts=-K1K
    if flag(hpc)
      ghc-options: -fhpc -hpcdir .hpc
  else
@@ -164,135 +174,97 @@ test-suite spec
  default-extensions: OverloadedStrings
                      QuasiQuotes
                      NoImplicitPrelude
-  hs-source-dirs:     test
+  hs-source-dirs:     test/spec
  main-is:            Main.hs
-  other-modules:      Feature.AndOrParamsSpec
-                      Feature.AsymmetricJwtSpec
-                      Feature.AudienceJwtSecretSpec
-                      Feature.AuthSpec
-                      Feature.BinaryJwtSecretSpec
+  other-modules:      Feature.Auth.AsymmetricJwtSpec
+                      Feature.Auth.AudienceJwtSecretSpec
+                      Feature.Auth.AuthSpec
+                      Feature.Auth.BinaryJwtSecretSpec
+                      Feature.Auth.NoAnonSpec
+                      Feature.Auth.NoJwtSpec
                      Feature.ConcurrentSpec
                      Feature.CorsSpec
-                      Feature.DeleteSpec
-                      Feature.DisabledOpenApiSpec
-                      Feature.EmbedDisambiguationSpec
-                      Feature.EmbedInnerJoinSpec
                      Feature.ExtraSearchPathSpec
-                      Feature.HtmlRawOutputSpec
-                      Feature.InsertSpec
-                      Feature.IgnorePrivOpenApiSpec
-                      Feature.JsonOperatorSpec
                      Feature.LegacyGucsSpec
-                      Feature.MultipleSchemaSpec
-                      Feature.NoJwtSpec
-                      Feature.NonexistentSchemaSpec
-                      Feature.OpenApiSpec
+                      Feature.OpenApi.DisabledOpenApiSpec
+                      Feature.OpenApi.IgnorePrivOpenApiSpec
+                      Feature.OpenApi.OpenApiSpec
+                      Feature.OpenApi.ProxySpec
+                      Feature.OpenApi.RootSpec
+                      Feature.OpenApi.SecurityOpenApiSpec
                      Feature.OptionsSpec
-                      Feature.ProxySpec
-                      Feature.QueryLimitedSpec
-                      Feature.QuerySpec
-                      Feature.RangeSpec
-                      Feature.RawOutputTypesSpec
+                      Feature.Query.AndOrParamsSpec
+                      Feature.Query.ComputedRelsSpec
+                      Feature.Query.DeleteSpec
+                      Feature.Query.EmbedDisambiguationSpec
+                      Feature.Query.EmbedInnerJoinSpec
+                      Feature.Query.PlanSpec
+                      Feature.Query.HtmlRawOutputSpec
+                      Feature.Query.InsertSpec
+                      Feature.Query.JsonOperatorSpec
+                      Feature.Query.MultipleSchemaSpec
+                      Feature.Query.ErrorSpec
+                      Feature.Query.PgSafeUpdateSpec
+                      Feature.Query.PostGISSpec
+                      Feature.Query.QueryLimitedSpec
+                      Feature.Query.QuerySpec
+                      Feature.Query.RangeSpec
+                      Feature.Query.RawOutputTypesSpec
+                      Feature.Query.RpcSpec
+                      Feature.Query.SingularSpec
+                      Feature.Query.UnicodeSpec
+                      Feature.Query.UpdateSpec
+                      Feature.Query.UpsertSpec
                      Feature.RollbackSpec
-                      Feature.RootSpec
                      Feature.RpcPreRequestGucsSpec
-                      Feature.RpcSpec
-                      Feature.SingularSpec
-                      Feature.UnicodeSpec
-                      Feature.UpdateSpec
-                      Feature.UpsertSpec
                      SpecHelper
                      TestTypes
-  build-depends:      base              >= 4.9 && < 4.16
-                    , aeson             >= 1.4.7 && < 1.6
+  build-depends:      base              >= 4.9 && < 4.17
+                    , aeson             >= 2.0.3 && < 2.2
                    , aeson-qq          >= 0.8.1 && < 0.9
                    , async             >= 2.1.1 && < 2.3
                    , auto-update       >= 0.1.4 && < 0.2
                    , base64-bytestring >= 1 && < 1.3
-                    , bytestring        >= 0.10.8 && < 0.11
+                    , bytestring        >= 0.10.8 && < 0.12
                    , case-insensitive  >= 1.2 && < 1.3
-                    , cassava           >= 0.4.5 && < 0.6
                    , containers        >= 0.5.7 && < 0.7
-                    , contravariant     >= 1.4 && < 1.6
-                    , hasql             >= 1.4 && < 1.5
-                    , hasql-pool        >= 0.5 && < 0.6
+                    , hasql-pool        >= 0.9 && < 0.10
                    , hasql-transaction >= 1.0.1 && < 1.1
                    , heredoc           >= 0.2 && < 0.3
-                    , hspec             >= 2.3 && < 2.9
+                    , hspec             >= 2.3 && < 2.10
                    , hspec-wai         >= 0.10 && < 0.12
                    , hspec-wai-json    >= 0.10 && < 0.12
                    , http-types        >= 0.12.3 && < 0.13
-                    , lens              >= 4.14 && < 5.1
-                    , lens-aeson        >= 1.0.1 && < 1.2
+                    , lens              >= 4.14 && < 5.3
+                    , lens-aeson        >= 1.0.1 && < 1.3
                    , monad-control     >= 1.0.1 && < 1.1
                    , postgrest
                    , process           >= 1.4.2 && < 1.7
-                    , protolude         >= 0.3 && < 0.4
+                    , protolude         >= 0.3.1 && < 0.4
                    , regex-tdfa        >= 1.2.2 && < 1.4
+                    , scientific        >= 0.3.4 && < 0.4
                    , text              >= 1.2.2 && < 1.3
-                    , time              >= 1.6 && < 1.11
                    , transformers-base >= 0.4.4 && < 0.5
                    , wai               >= 3.2.1 && < 3.3
                    , wai-extra         >= 3.0.19 && < 3.2
-  ghc-options:        -O0 -Werror -Wall -fwarn-identities
+  ghc-options:        -threaded -O0 -Werror -Wall -fwarn-identities
                      -fno-spec-constr -optP-Wno-nonportable-include-path
                      -fno-warn-missing-signatures
-
-test-suite querycost
-  type:                exitcode-stdio-1.0
-  default-language:    Haskell2010
-  default-extensions:  OverloadedStrings
-                       QuasiQuotes
-                       NoImplicitPrelude
-  hs-source-dirs:      test
-  main-is:             QueryCost.hs
-  other-modules:       SpecHelper
-  build-depends:       base              >= 4.9 && < 4.16
-                     , aeson             >= 1.4.7 && < 1.6
-                     , aeson-qq          >= 0.8.1 && < 0.9
-                     , async             >= 2.1.1 && < 2.3
-                     , auto-update       >= 0.1.4 && < 0.2
-                     , base64-bytestring >= 1 && < 1.3
-                     , bytestring        >= 0.10.8 && < 0.11
-                     , case-insensitive  >= 1.2 && < 1.3
-                     , cassava           >= 0.4.5 && < 0.6
-                     , containers        >= 0.5.7 && < 0.7
-                     , contravariant     >= 1.4 && < 1.6
-                     , hasql             >= 1.4 && < 1.5
-                     , hasql-dynamic-statements  == 0.3.1
-                     , hasql-pool        >= 0.5 && < 0.6
-                     , hasql-transaction >= 1.0.1 && < 1.1
-                     , heredoc           >= 0.2 && < 0.3
-                     , hspec             >= 2.3 && < 2.9
-                     , hspec-wai         >= 0.10 && < 0.12
-                     , hspec-wai-json    >= 0.10 && < 0.12
-                     , http-types        >= 0.12.3 && < 0.13
-                     , lens              >= 4.14 && < 5.1
-                     , lens-aeson        >= 1.0.1 && < 1.2
-                     , monad-control     >= 1.0.1 && < 1.1
-                     , postgrest
-                     , process           >= 1.4.2 && < 1.7
-                     , protolude         >= 0.3 && < 0.4
-                     , regex-tdfa        >= 1.2.2 && < 1.4
-                     , text              >= 1.2.2 && < 1.3
-                     , time              >= 1.6 && < 1.11
-                     , transformers-base >= 0.4.4 && < 0.5
-                     , wai               >= 3.2.1 && < 3.3
-                     , wai-extra         >= 3.0.19 && < 3.2
-  ghc-options:         -O0 -Werror -Wall -fwarn-identities
-                       -fno-spec-constr -optP-Wno-nonportable-include-path
+                      -fwrite-ide-info
+                      -- https://github.com/PostgREST/postgrest/issues/387
+                      -with-rtsopts=-K33K

 test-suite doctests
-  type:                exitcode-stdio-1.0
-  default-language:    Haskell2010
-  default-extensions:  OverloadedStrings
-                       NoImplicitPrelude
-  hs-source-dirs:      test/doctests
-  main-is:             Main.hs
-  build-depends:       base              >= 4.9 && < 4.16
-                     , doctest           >= 0.8
-                     , postgrest
-                     , pretty-simple
-                     , protolude         >= 0.3 && < 0.4
-  ghc-options:         -threaded -O0 -Werror -Wall -fwarn-identities
-                       -fno-spec-constr -optP-Wno-nonportable-include-path
+  type:               exitcode-stdio-1.0
+  default-language:   Haskell2010
+  default-extensions: OverloadedStrings
+                      NoImplicitPrelude
+  hs-source-dirs:     test/doc
+  main-is:            Main.hs
+  build-depends:      base              >= 4.9 && < 4.17
+                    , doctest           >= 0.8
+                    , postgrest
+                    , pretty-simple
+                    , protolude         >= 0.3.1 && < 0.4
+  ghc-options:        -threaded -O0 -Werror -Wall -fwarn-identities
+                      -fno-spec-constr -optP-Wno-nonportable-include-path
@@ -11,7 +11,7 @@
 }:
 let
  postgrest =
-    import ./default.nix;
+    import ./default.nix { };

  inherit (postgrest) pkgs;

@@ -21,6 +21,7 @@ let
    [
      postgrest.cabalTools
      postgrest.devTools
+      postgrest.loadtest
      postgrest.nixpkgsTools
      postgrest.style
      postgrest.tests
@@ -37,20 +38,25 @@ lib.overrideDerivation postgrest.env (
      base.buildInputs ++ [
        pkgs.cabal-install
        pkgs.cabal2nix
+        pkgs.git
        pkgs.postgresql
+        pkgs.update-nix-fetchgit
        postgrest.hsie.bin
      ]
      ++ toolboxes;

    shellHook =
      ''
-        source ${pkgs.bashCompletion}/etc/profile.d/bash_completion.sh
-        source ${postgrest.hsie.bashCompletion}
+        export HISTFILE=.history
+
+        source ${pkgs.bash-completion}/etc/profile.d/bash_completion.sh
+        source ${pkgs.git}/share/git/contrib/completion/git-completion.bash
+        source ${postgrest.hsie.bash-completion}

      ''
      + builtins.concatStringsSep "\n" (
-        builtins.map (bashCompletion: "source ${bashCompletion}") (
-          builtins.concatLists (builtins.map (toolbox: toolbox.bashCompletion) toolboxes)
+        builtins.map (bash-completion: "source ${bash-completion}") (
+          builtins.concatLists (builtins.map (toolbox: toolbox.bash-completion) toolboxes)
        )
      );
  }
@@ -0,0 +1,536 @@
+{-|
+Module      : PostgREST.Request.ApiRequest
+Description : PostgREST functions to translate HTTP request to a domain type called ApiRequest.
+-}
+{-# LANGUAGE LambdaCase      #-}
+{-# LANGUAGE NamedFieldPuns  #-}
+{-# LANGUAGE RecordWildCards #-}
+
+module PostgREST.ApiRequest
+  ( ApiRequest(..)
+  , InvokeMethod(..)
+  , Mutation(..)
+  , MediaType(..)
+  , Action(..)
+  , Target(..)
+  , Payload(..)
+  , userApiRequest
+  ) where
+
+import qualified Data.Aeson            as JSON
+import qualified Data.Aeson.Key        as K
+import qualified Data.Aeson.KeyMap     as KM
+import qualified Data.ByteString.Char8 as BS
+import qualified Data.ByteString.Lazy  as LBS
+import qualified Data.CaseInsensitive  as CI
+import qualified Data.Csv              as CSV
+import qualified Data.HashMap.Strict   as HM
+import qualified Data.List             as L
+import qualified Data.List.NonEmpty    as NonEmptyList
+import qualified Data.Map.Strict       as M
+import qualified Data.Set              as S
+import qualified Data.Text.Encoding    as T
+import qualified Data.Vector           as V
+
+import Control.Arrow             ((***))
+import Data.Aeson.Types          (emptyArray, emptyObject)
+import Data.List                 (lookup, union)
+import Data.Ranged.Ranges        (emptyRange, rangeIntersection,
+                                  rangeIsEmpty)
+import Data.Tree                 (Tree (..))
+import Network.HTTP.Types.Header (RequestHeaders, hCookie)
+import Network.HTTP.Types.URI    (parseSimpleQuery)
+import Network.Wai               (Request (..))
+import Network.Wai.Parse         (parseHttpAccept)
+import Web.Cookie                (parseCookies)
+
+import PostgREST.ApiRequest.Preferences  (PreferCount (..),
+                                          PreferParameters (..),
+                                          PreferRepresentation (..),
+                                          PreferResolution (..),
+                                          PreferTransaction (..))
+import PostgREST.ApiRequest.QueryParams  (QueryParams (..))
+import PostgREST.ApiRequest.Types        (ApiRequestError (..),
+                                          RangeError (..),
+                                          SelectItem (..))
+import PostgREST.Config                  (AppConfig (..),
+                                          OpenAPIMode (..))
+import PostgREST.MediaType               (MTPlanAttrs (..),
+                                          MTPlanFormat (..),
+                                          MediaType (..))
+import PostgREST.RangeQuery              (NonnegRange, allRange,
+                                          convertToLimitZeroRange,
+                                          hasLimitZero,
+                                          rangeRequested)
+import PostgREST.SchemaCache             (SchemaCache (..))
+import PostgREST.SchemaCache.Identifiers (FieldName,
+                                          QualifiedIdentifier (..),
+                                          Schema)
+import PostgREST.SchemaCache.Proc        (ProcDescription (..),
+                                          ProcParam (..), ProcsMap,
+                                          procReturnsScalar)
+
+import qualified PostgREST.ApiRequest.Preferences as Preferences
+import qualified PostgREST.ApiRequest.QueryParams as QueryParams
+import qualified PostgREST.MediaType              as MediaType
+
+import Protolude
+
+
+type RequestBody = LBS.ByteString
+
+data Payload
+  = ProcessedJSON -- ^ Cached attributes of a JSON payload
+      { payRaw  :: LBS.ByteString
+      -- ^ This is the raw ByteString that comes from the request body.  We
+      -- cache this instead of an Aeson Value because it was detected that for
+      -- large payloads the encoding had high memory usage, see
+      -- https://github.com/PostgREST/postgrest/pull/1005 for more details
+      , payKeys :: S.Set Text
+      -- ^ Keys of the object or if it's an array these keys are guaranteed to
+      -- be the same across all its objects
+      }
+  | RawJSON { payRaw  :: LBS.ByteString }
+  | RawPay  { payRaw  :: LBS.ByteString }
+
+data InvokeMethod = InvHead | InvGet | InvPost deriving Eq
+data Mutation = MutationCreate | MutationDelete | MutationSingleUpsert | MutationUpdate deriving Eq
+
+-- | Types of things a user wants to do to tables/views/procs
+data Action
+  = ActionMutate Mutation
+  | ActionRead {isHead :: Bool}
+  | ActionInvoke InvokeMethod
+  | ActionInfo
+  | ActionInspect {isHead :: Bool}
+  deriving Eq
+-- | The path info that will be mapped to a target (used to handle validations and errors before defining the Target)
+data PathInfo
+  = PathInfo
+      { pathName       :: Text
+      , pathIsProc     :: Bool
+      , pathIsDefSpec  :: Bool
+      , pathIsRootSpec :: Bool
+      }
+-- | The target db object of a user action
+data Target = TargetIdent QualifiedIdentifier
+            | TargetProc{tProc :: ProcDescription, tpIsRootSpec :: Bool}
+            | TargetDefaultSpec{tdsSchema :: Schema} -- The default spec offered at root "/"
+
+-- | RPC query param value `/rpc/func?v=<value>`, used for VARIADIC functions on form-urlencoded POST and GETs
+-- | It can be fixed `?v=1` or repeated `?v=1&v=2&v=3.
+data RpcParamValue = Fixed Text | Variadic [Text]
+instance JSON.ToJSON RpcParamValue where
+  toJSON (Fixed    v) = JSON.toJSON v
+  toJSON (Variadic v) = JSON.toJSON v
+
+toRpcParamValue :: ProcDescription -> (Text, Text) -> (Text, RpcParamValue)
+toRpcParamValue proc (k, v) | prmIsVariadic k = (k, Variadic [v])
+                            | otherwise       = (k, Fixed v)
+  where
+    prmIsVariadic prm = isJust $ find (\ProcParam{ppName, ppVar} -> ppName == prm && ppVar) $ pdParams proc
+
+-- | Convert rpc params `/rpc/func?a=val1&b=val2` to json `{"a": "val1", "b": "val2"}
+jsonRpcParams :: ProcDescription -> [(Text, Text)] -> Payload
+jsonRpcParams proc prms =
+  if not $ pdHasVariadic proc then -- if proc has no variadic param, save steps and directly convert to json
+    ProcessedJSON (JSON.encode $ HM.fromList $ second JSON.toJSON <$> prms) (S.fromList $ fst <$> prms)
+  else
+    let paramsMap = HM.fromListWith mergeParams $ toRpcParamValue proc <$> prms in
+    ProcessedJSON (JSON.encode paramsMap) (S.fromList $ HM.keys paramsMap)
+  where
+    mergeParams :: RpcParamValue -> RpcParamValue -> RpcParamValue
+    mergeParams (Variadic a) (Variadic b) = Variadic $ b ++ a
+    mergeParams v _                       = v -- repeated params for non-variadic parameters are not merged
+
+targetToJsonRpcParams :: Maybe Target -> [(Text, Text)] -> Maybe Payload
+targetToJsonRpcParams target params =
+  case target of
+    Just TargetProc{tProc} -> Just $ jsonRpcParams tProc params
+    _                      -> Nothing
+
+{-|
+  Describes what the user wants to do. This data type is a
+  translation of the raw elements of an HTTP request into domain
+  specific language.  There is no guarantee that the intent is
+  sensible, it is up to a later stage of processing to determine
+  if it is an action we are able to perform.
+-}
+data ApiRequest = ApiRequest {
+    iAction               :: Action                           -- ^ Similar but not identical to HTTP method, e.g. Create/Invoke both POST
+  , iRange                :: HM.HashMap Text NonnegRange      -- ^ Requested range of rows within response
+  , iTopLevelRange        :: NonnegRange                      -- ^ Requested range of rows from the top level
+  , iTarget               :: Target                           -- ^ The target, be it calling a proc or accessing a table
+  , iPayload              :: Maybe Payload                    -- ^ Data sent by client and used for mutation actions
+  , iPreferRepresentation :: PreferRepresentation             -- ^ If client wants created items echoed back
+  , iPreferParameters     :: Maybe PreferParameters           -- ^ How to pass parameters to a stored procedure
+  , iPreferCount          :: Maybe PreferCount                -- ^ Whether the client wants a result count
+  , iPreferResolution     :: Maybe PreferResolution           -- ^ Whether the client wants to UPSERT or ignore records on PK conflict
+  , iPreferTransaction    :: Maybe PreferTransaction          -- ^ Whether the clients wants to commit or rollback the transaction
+  , iQueryParams          :: QueryParams.QueryParams
+  , iColumns              :: S.Set FieldName                  -- ^ parsed colums from &columns parameter and payload
+  , iHeaders              :: [(ByteString, ByteString)]       -- ^ HTTP request headers
+  , iCookies              :: [(ByteString, ByteString)]       -- ^ Request Cookies
+  , iPath                 :: ByteString                       -- ^ Raw request path
+  , iMethod               :: ByteString                       -- ^ Raw request method
+  , iSchema               :: Schema                           -- ^ The request schema. Can vary depending on profile headers.
+  , iNegotiatedByProfile  :: Bool                             -- ^ If schema was was chosen according to the profile spec https://www.w3.org/TR/dx-prof-conneg/
+  , iAcceptMediaType      :: MediaType                        -- ^ The media type in the Accept header
+  , iBinaryField          :: Maybe FieldName                  -- ^ field used for raw output
+  }
+
+-- | Examines HTTP request and translates it into user intent.
+userApiRequest :: AppConfig -> SchemaCache -> Request -> RequestBody -> Either ApiRequestError ApiRequest
+userApiRequest conf sCache req reqBody = do
+  qPrms <- first QueryParamError $ QueryParams.parse $ rawQueryString req
+  pInfo <- getPathInfo conf $ pathInfo req
+  act <- getAction pInfo $ requestMethod req
+  mediaTypes <- getMediaTypes conf (requestHeaders req) act pInfo
+  negotiatedSchema <- getSchema conf (requestHeaders req) (requestMethod req)
+  apiRequest conf sCache req reqBody qPrms pInfo act mediaTypes negotiatedSchema
+
+getPathInfo :: AppConfig -> [Text] -> Either ApiRequestError PathInfo
+getPathInfo AppConfig{configOpenApiMode, configDbRootSpec} path =
+  case path of
+    []             -> case configDbRootSpec of
+                        Just (QualifiedIdentifier _ pathName)     -> Right $ PathInfo pathName True False True
+                        Nothing | configOpenApiMode == OADisabled -> Left NotFound
+                                | otherwise                       -> Right $ PathInfo mempty False True False
+    [table]        -> Right $ PathInfo table False False False
+    ["rpc", pName] -> Right $ PathInfo pName True False False
+    _              -> Left NotFound
+
+getAction :: PathInfo -> ByteString -> Either ApiRequestError Action
+getAction PathInfo{pathIsProc, pathIsDefSpec} method =
+  if pathIsProc && method `notElem` ["HEAD", "GET", "POST", "OPTIONS"]
+    then Left $ InvalidRpcMethod method
+    else case method of
+      -- The HEAD method is identical to GET except that the server MUST NOT return a message-body in the response
+      -- From https://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html#sec9.4
+      "HEAD"     | pathIsDefSpec -> Right $ ActionInspect{isHead=True}
+                 | pathIsProc    -> Right $ ActionInvoke InvHead
+                 | otherwise     -> Right $ ActionRead{isHead=True}
+      "GET"      | pathIsDefSpec -> Right $ ActionInspect{isHead=False}
+                 | pathIsProc    -> Right $ ActionInvoke InvGet
+                 | otherwise     -> Right $ ActionRead{isHead=False}
+      "POST"     | pathIsProc    -> Right $ ActionInvoke InvPost
+                 | otherwise     -> Right $ ActionMutate MutationCreate
+      "PATCH"                    -> Right $ ActionMutate MutationUpdate
+      "PUT"                      -> Right $ ActionMutate MutationSingleUpsert
+      "DELETE"                   -> Right $ ActionMutate MutationDelete
+      "OPTIONS"                  -> Right ActionInfo
+      _                          -> Left $ UnsupportedMethod method
+
+getMediaTypes :: AppConfig -> RequestHeaders -> Action -> PathInfo -> Either ApiRequestError (MediaType, MediaType)
+getMediaTypes conf hdrs action path = do
+   acceptMediaType <- findAcceptMediaType conf action path accepts
+   pure (acceptMediaType, contentMediaType)
+  where
+    accepts = maybe [MTAny] (map MediaType.decodeMediaType . parseHttpAccept) $ lookupHeader "accept"
+    contentMediaType = maybe MTApplicationJSON MediaType.decodeMediaType $ lookupHeader "content-type"
+    lookupHeader    = flip lookup hdrs
+
+getSchema :: AppConfig -> RequestHeaders -> ByteString -> Either ApiRequestError (Schema, Bool)
+getSchema AppConfig{configDbSchemas} hdrs method = do
+  case profile of
+    Just p | p `notElem` configDbSchemas -> Left $ UnacceptableSchema $ toList configDbSchemas
+           | otherwise                   -> Right (p, True)
+    Nothing -> Right (defaultSchema, length configDbSchemas /= 1) -- if we have many schemas, assume the default schema was negotiated
+  where
+    defaultSchema = NonEmptyList.head configDbSchemas
+    profile = case method of
+      -- POST/PATCH/PUT/DELETE don't use the same header as per the spec
+      "DELETE" -> contentProfile
+      "PATCH"  -> contentProfile
+      "POST"   -> contentProfile
+      "PUT"    -> contentProfile
+      _        -> acceptProfile
+    contentProfile = T.decodeUtf8 <$> lookupHeader "Content-Profile"
+    acceptProfile = T.decodeUtf8 <$> lookupHeader "Accept-Profile"
+    lookupHeader    = flip lookup hdrs
+
+apiRequest :: AppConfig -> SchemaCache -> Request -> RequestBody -> QueryParams.QueryParams -> PathInfo -> Action -> (MediaType, MediaType) -> (Schema, Bool) -> Either ApiRequestError ApiRequest
+apiRequest conf sCache req reqBody queryparams@QueryParams{..} PathInfo{pathName, pathIsProc, pathIsRootSpec, pathIsDefSpec} action (acceptMediaType, contentMediaType) (schema, negotiatedByProfile)
+  | isInvalidRange = Left $ InvalidRange (if rangeIsEmpty headerRange then LowerGTUpper else NegativeLimit)
+  | shouldParsePayload && isLeft payload = either (Left . InvalidBody) witness payload
+  | not expectParams && not (L.null qsParams) = Left $ ParseRequestError "Unexpected param or filter missing operator" ("Failed to parse " <> show qsParams)
+  | method `elem` ["PATCH", "DELETE"] && not (null qsRanges) && null qsOrder = Left LimitNoOrderError
+  | method == "PUT" && topLevelRange /= allRange = Left PutRangeNotAllowedError
+  | otherwise = do
+     checkedTarget <- target
+     bField <- binaryField conf acceptMediaType checkedTarget queryparams
+     return ApiRequest {
+      iAction = action
+      , iTarget = checkedTarget
+      , iRange = ranges
+      , iTopLevelRange = topLevelRange
+      , iPayload = relevantPayload
+      , iPreferRepresentation = fromMaybe None preferRepresentation
+      , iPreferParameters = preferParameters
+      , iPreferCount = preferCount
+      , iPreferResolution = preferResolution
+      , iPreferTransaction = preferTransaction
+      , iQueryParams = queryparams
+      , iColumns = payloadColumns
+      , iHeaders = [ (CI.foldedCase k, v) | (k,v) <- hdrs, k /= hCookie]
+      , iCookies = maybe [] parseCookies $ lookupHeader "Cookie"
+      , iPath = rawPathInfo req
+      , iMethod = method
+      , iSchema = schema
+      , iNegotiatedByProfile = negotiatedByProfile
+      , iAcceptMediaType = acceptMediaType
+      , iBinaryField = bField
+      }
+ where
+  expectParams = pathIsProc && method /= "POST"
+
+  columns = case action of
+    ActionMutate MutationCreate -> qsColumns
+    ActionMutate MutationUpdate -> qsColumns
+    ActionInvoke InvPost        -> qsColumns
+    _                           -> Nothing
+
+  payloadColumns =
+    case (contentMediaType, action) of
+      (_, ActionInvoke InvGet)  -> S.fromList $ fst <$> qsParams
+      (_, ActionInvoke InvHead) -> S.fromList $ fst <$> qsParams
+      (MTUrlEncoded, _)         -> S.fromList $ map (T.decodeUtf8 . fst) $ parseSimpleQuery $ LBS.toStrict reqBody
+      _ -> case (relevantPayload, columns) of
+        (Just ProcessedJSON{payKeys}, _) -> payKeys
+        (Just RawJSON{}, Just cls)       -> cls
+        _                                -> S.empty
+  payload :: Either ByteString Payload
+  payload = case (contentMediaType, pathIsProc) of
+    (MTApplicationJSON, _) ->
+      if isJust columns
+        then Right $ RawJSON reqBody
+        else note "All object keys must match" . payloadAttributes reqBody
+               =<< if LBS.null reqBody && pathIsProc
+                     then Right emptyObject
+                     else first BS.pack $ JSON.eitherDecode reqBody
+    (MTTextCSV, _) -> do
+      json <- csvToJson <$> first BS.pack (CSV.decodeByName reqBody)
+      note "All lines must have same number of fields" $ payloadAttributes (JSON.encode json) json
+    (MTUrlEncoded, _) ->
+      let paramsMap = HM.fromList $ (T.decodeUtf8 *** JSON.String . T.decodeUtf8) <$> parseSimpleQuery (LBS.toStrict reqBody) in
+      Right $ ProcessedJSON (JSON.encode paramsMap) $ S.fromList (HM.keys paramsMap)
+    (MTTextPlain, True) -> Right $ RawPay reqBody
+    (MTTextXML, True) -> Right $ RawPay reqBody
+    (MTOctetStream, True) -> Right $ RawPay reqBody
+    (ct, _) -> Left $ "Content-Type not acceptable: " <> MediaType.toMime ct
+  topLevelRange = fromMaybe allRange $ HM.lookup "limit" ranges -- if no limit is specified, get all the request rows
+
+  target
+    | pathIsProc    = (`TargetProc` pathIsRootSpec) <$> callFindProc schema pathName
+    | pathIsDefSpec = Right $ TargetDefaultSpec schema
+    | otherwise     = Right $ TargetIdent $ QualifiedIdentifier schema pathName
+    where
+      callFindProc procSch procNam = findProc
+        (QualifiedIdentifier procSch procNam) payloadColumns (preferParameters == Just SingleObject) (dbProcs sCache)
+        contentMediaType (action == ActionInvoke InvPost)
+
+  shouldParsePayload = case (action, contentMediaType) of
+    (ActionMutate MutationCreate, _)       -> True
+    (ActionInvoke InvPost, MTUrlEncoded)   -> False
+    (ActionInvoke InvPost, _)              -> True
+    (ActionMutate MutationSingleUpsert, _) -> True
+    (ActionMutate MutationUpdate, _)       -> True
+    _                                      -> False
+  relevantPayload = case (contentMediaType, action) of
+    -- Though ActionInvoke GET/HEAD doesn't really have a payload, we use the payload variable as a way
+    -- to store the query string arguments to the function.
+    (_, ActionInvoke InvGet)             -> targetToJsonRpcParams (rightToMaybe target) qsParams
+    (_, ActionInvoke InvHead)            -> targetToJsonRpcParams (rightToMaybe target) qsParams
+    (MTUrlEncoded, ActionInvoke InvPost) -> targetToJsonRpcParams (rightToMaybe target) $ (T.decodeUtf8 *** T.decodeUtf8) <$> parseSimpleQuery (LBS.toStrict reqBody)
+    _ | shouldParsePayload               -> rightToMaybe payload
+      | otherwise                        -> Nothing
+  method          = requestMethod req
+  hdrs            = requestHeaders req
+  lookupHeader    = flip lookup hdrs
+  Preferences.Preferences{..} = Preferences.fromHeaders hdrs
+  headerRange = rangeRequested hdrs
+  limitRange = fromMaybe allRange (HM.lookup "limit" qsRanges)
+  headerAndLimitRange = rangeIntersection headerRange limitRange
+
+  -- Bypass all the ranges and send only the limit zero range (0 <= x <= -1) if
+  -- limit=0 is present in the query params (not allowed for the Range header)
+  ranges = HM.insert "limit" (convertToLimitZeroRange limitRange headerAndLimitRange) qsRanges
+  -- The only emptyRange allowed is the limit zero range
+  isInvalidRange = topLevelRange == emptyRange && not (hasLimitZero limitRange)
+
+{-|
+  Find the best match from a list of media types accepted by the
+  client in order of decreasing preference and a list of types
+  producible by the server.  If there is no match but the client
+  accepts */* then return the top server pick.
+-}
+mutuallyAgreeable :: [MediaType] -> [MediaType] -> Maybe MediaType
+mutuallyAgreeable sProduces cAccepts =
+  let exact = listToMaybe $ L.intersect cAccepts sProduces in
+  if isNothing exact && MTAny `elem` cAccepts
+     then listToMaybe sProduces
+     else exact
+
+type CsvData = V.Vector (M.Map Text LBS.ByteString)
+
+{-|
+  Converts CSV like
+  a,b
+  1,hi
+  2,bye
+
+  into a JSON array like
+  [ {"a": "1", "b": "hi"}, {"a": 2, "b": "bye"} ]
+
+  The reason for its odd signature is so that it can compose
+  directly with CSV.decodeByName
+-}
+csvToJson :: (CSV.Header, CsvData) -> JSON.Value
+csvToJson (_, vals) =
+  JSON.Array $ V.map rowToJsonObj vals
+ where
+  rowToJsonObj = JSON.Object . KM.fromMapText .
+    M.map (\str ->
+        if str == "NULL"
+          then JSON.Null
+          else JSON.String . T.decodeUtf8 $ LBS.toStrict str
+      )
+
+payloadAttributes :: RequestBody -> JSON.Value -> Maybe Payload
+payloadAttributes raw json =
+  -- Test that Array contains only Objects having the same keys
+  case json of
+    JSON.Array arr ->
+      case arr V.!? 0 of
+        Just (JSON.Object o) ->
+          let canonicalKeys = S.fromList $ K.toText <$> KM.keys o
+              areKeysUniform = all (\case
+                JSON.Object x -> S.fromList (K.toText <$> KM.keys x) == canonicalKeys
+                _ -> False) arr in
+          if areKeysUniform
+            then Just $ ProcessedJSON raw canonicalKeys
+            else Nothing
+        Just _ -> Nothing
+        Nothing -> Just emptyPJArray
+
+    JSON.Object o -> Just $ ProcessedJSON raw (S.fromList $ K.toText <$> KM.keys o)
+
+    -- truncate everything else to an empty array.
+    _ -> Just emptyPJArray
+  where
+    emptyPJArray = ProcessedJSON (JSON.encode emptyArray) S.empty
+
+findAcceptMediaType :: AppConfig -> Action -> PathInfo -> [MediaType] -> Either ApiRequestError MediaType
+findAcceptMediaType conf action path accepts =
+  case mutuallyAgreeable (requestMediaTypes conf action path) accepts of
+    Just ct ->
+      Right ct
+    Nothing ->
+      Left . MediaTypeError $ map MediaType.toMime accepts
+
+requestMediaTypes :: AppConfig -> Action -> PathInfo -> [MediaType]
+requestMediaTypes conf action path =
+  case action of
+    ActionRead _    -> defaultMediaTypes ++ rawMediaTypes
+    ActionInvoke _  -> invokeMediaTypes
+    ActionInspect _ -> [MTOpenAPI, MTApplicationJSON]
+    ActionInfo      -> [MTTextCSV]
+    _               -> defaultMediaTypes
+  where
+    invokeMediaTypes =
+      defaultMediaTypes
+        ++ rawMediaTypes
+        ++ [MTOpenAPI | pathIsRootSpec path]
+    defaultMediaTypes =
+      [MTApplicationJSON, MTSingularJSON, MTGeoJSON, MTTextCSV] ++
+      [MTPlan $ MTPlanAttrs Nothing PlanJSON mempty | configDbPlanEnabled conf]
+    rawMediaTypes = configRawMediaTypes conf `union` [MTOctetStream, MTTextPlain, MTTextXML]
+
+{-|
+  Search a pg proc by matching name and arguments keys to parameters. Since a function can be overloaded,
+  the name is not enough to find it. An overloaded function can have a different volatility or even a different return type.
+-}
+findProc :: QualifiedIdentifier -> S.Set Text -> Bool -> ProcsMap -> MediaType -> Bool -> Either ApiRequestError ProcDescription
+findProc qi argumentsKeys paramsAsSingleObject allProcs contentMediaType isInvPost =
+  case matchProc of
+    ([], [])     -> Left $ NoRpc (qiSchema qi) (qiName qi) (S.toList argumentsKeys) paramsAsSingleObject contentMediaType isInvPost (HM.keys allProcs) lookupProcName
+    -- If there are no functions with named arguments, fallback to the single unnamed argument function
+    ([], [proc]) -> Right proc
+    ([], procs)  -> Left $ AmbiguousRpc (toList procs)
+    -- Matches the functions with named arguments
+    ([proc], _)  -> Right proc
+    (procs, _)   -> Left $ AmbiguousRpc (toList procs)
+  where
+    matchProc = overloadedProcPartition lookupProcName
+    -- First find the proc by name
+    lookupProcName = HM.lookupDefault mempty qi allProcs
+    -- The partition obtained has the form (overloadedProcs,fallbackProcs)
+    -- where fallbackProcs are functions with a single unnamed parameter
+    overloadedProcPartition = foldr select ([],[])
+    select proc ~(ts,fs)
+      | matchesParams proc         = (proc:ts,fs)
+      | hasSingleUnnamedParam proc = (ts,proc:fs)
+      | otherwise                  = (ts,fs)
+    -- If the function is called with post and has a single unnamed parameter
+    -- it can be called depending on content type and the parameter type
+    hasSingleUnnamedParam ProcDescription{pdParams=[ProcParam{ppType}]} = isInvPost && case (contentMediaType, ppType) of
+      (MTApplicationJSON, "json")  -> True
+      (MTApplicationJSON, "jsonb") -> True
+      (MTTextPlain, "text")        -> True
+      (MTTextXML, "xml")           -> True
+      (MTOctetStream, "bytea")     -> True
+      _                            -> False
+    hasSingleUnnamedParam _ = False
+    matchesParams proc =
+      let
+        params = pdParams proc
+        firstType = (ppType <$> headMay params)
+      in
+      -- exceptional case for Prefer: params=single-object
+      if paramsAsSingleObject
+        then length params == 1 && (firstType == Just "json" || firstType == Just "jsonb")
+      -- If the function has no parameters, the arguments keys must be empty as well
+      else if null params
+        then null argumentsKeys && not (isInvPost && contentMediaType `elem` [MTOctetStream, MTTextPlain, MTTextXML])
+      -- A function has optional and required parameters. Optional parameters have a default value and
+      -- don't require arguments for the function to be executed, required parameters must have an argument present.
+      else case L.partition ppReq params of
+      -- If the function only has required parameters, the arguments keys must match those parameters
+        (reqParams, [])        -> argumentsKeys == S.fromList (ppName <$> reqParams)
+      -- If the function only has optional parameters, the arguments keys can match none or any of them(a subset)
+        ([], optParams)        -> argumentsKeys `S.isSubsetOf` S.fromList (ppName <$> optParams)
+      -- If the function has required and optional parameters, the arguments keys have to match the required parameters
+      -- and can match any or none of the default parameters.
+        (reqParams, optParams) -> argumentsKeys `S.difference` S.fromList (ppName <$> optParams) == S.fromList (ppName <$> reqParams)
+
+-- | If raw(binary) output is requested, check that MediaType is one of the
+-- admitted rawMediaTypes and that`?select=...` contains only one field other
+-- than `*`
+binaryField :: AppConfig -> MediaType -> Target -> QueryParams -> Either ApiRequestError (Maybe FieldName)
+binaryField AppConfig{configRawMediaTypes} acceptMediaType target QueryParams{qsSelect}
+  | returnsScalar target && isRawMediaType =
+      Right $ Just "pgrst_scalar"
+  | isRawMediaType =
+      let
+        fieldName = fstFieldName qsSelect
+      in
+      case fieldName of
+        Just fld -> Right $ Just fld
+        Nothing  -> Left $ BinaryFieldError acceptMediaType
+  | otherwise =
+      Right Nothing
+  where
+    isRawMediaType = acceptMediaType `elem` configRawMediaTypes `union` [MTOctetStream, MTTextPlain, MTTextXML] || isRawPlan acceptMediaType
+    isRawPlan mt = case mt of
+      MTPlan (MTPlanAttrs (Just MTOctetStream) _ _) -> True
+      MTPlan (MTPlanAttrs (Just MTTextPlain) _ _)   -> True
+      MTPlan (MTPlanAttrs (Just MTTextXML) _ _)     -> True
+      _                                             -> False
+    returnsScalar :: Target -> Bool
+    returnsScalar (TargetProc proc _) = procReturnsScalar proc
+    returnsScalar _                   = False
+
+    fstFieldName :: [Tree SelectItem] -> Maybe FieldName
+    fstFieldName [Node SelectField{selField=("*", _)} []] = Nothing
+    fstFieldName [Node SelectField{selField=(fld, _)} []] = Just fld
+    fstFieldName _                                        = Nothing
@@ -1,12 +1,12 @@
 -- |
-- Module: PostgREST.Request.Preferences
+-- Module: PostgREST.ApiRequest.Preferences
 -- Description: Track client preferences to be employed when processing requests
 --
 -- Track client prefences set in HTTP 'Prefer' headers according to RFC7240[1].
 --
 -- [1] https://datatracker.ietf.org/doc/html/rfc7240
 --
-module PostgREST.Request.Preferences
+module PostgREST.ApiRequest.Preferences
  ( Preferences(..)
  , PreferCount(..)
  , PreferParameters(..)
@@ -15,6 +15,7 @@ module PostgREST.Request.Preferences
  , PreferTransaction(..)
  , fromHeaders
  , ToAppliedHeader(..)
+  , shouldCount
  ) where

 import qualified Data.ByteString.Char8     as BS
@@ -155,7 +156,7 @@ instance ToAppliedHeader PreferResolution
 --
 -- From https://tools.ietf.org/html/rfc7240#section-4.2
 data PreferRepresentation
-  = Full        -- ^ Return the body plus the Location header(in case of POST).
+  = Full        -- ^ Return the body.
  | HeadersOnly -- ^ Return the Location header(in case of POST). This needs a SELECT privilege on the pk.
  | None        -- ^ Return nothing from the mutated data.
  deriving Eq
@@ -171,6 +172,7 @@ data PreferParameters
  | MultipleObjects -- ^ Pass an array of json objects as params to a stored procedure.
  deriving Eq

+-- TODO: Deprecate params=multiple-objects in next major version
 instance ToHeaderValue PreferParameters where
  toHeaderValue SingleObject    = "params=single-object"
  toHeaderValue MultipleObjects = "params=multiple-objects"
@@ -187,6 +189,10 @@ instance ToHeaderValue PreferCount where
  toHeaderValue PlannedCount   = "count=planned"
  toHeaderValue EstimatedCount = "count=estimated"

+shouldCount :: Maybe PreferCount -> Bool
+shouldCount prefCount =
+  prefCount == Just ExactCount || prefCount == Just EstimatedCount
+
 -- | Whether to commit or roll back transactions.
 data PreferTransaction
  = Commit   -- ^ Commit transaction - the default.
@@ -0,0 +1,653 @@
+-- |
+-- Module      : PostgREST.ApiRequest.QueryParams
+-- Description : Parser for PostgREST Query parameters
+--
+-- This module is in charge of parsing all the querystring values in an url, e.g.
+-- the select, id, order in `/projects?select=id,name&id=eq.1&order=id,name.desc`.
+{-# LANGUAGE LambdaCase    #-}
+{-# LANGUAGE TupleSections #-}
+module PostgREST.ApiRequest.QueryParams
+  ( parse
+  , QueryParams(..)
+  , pRequestRange
+  ) where
+
+import qualified Data.ByteString.Char8         as BS
+import qualified Data.HashMap.Strict           as HM
+import qualified Data.List                     as L
+import qualified Data.Set                      as S
+import qualified Data.Text                     as T
+import qualified Data.Text.Encoding            as T
+import qualified Network.HTTP.Base             as HTTP
+import qualified Network.HTTP.Types.URI        as HTTP
+import qualified Text.ParserCombinators.Parsec as P
+
+import Control.Arrow                 ((***))
+import Data.Either.Combinators       (mapLeft)
+import Data.List                     (init, last)
+import Data.Ranged.Boundaries        (Boundary (..))
+import Data.Ranged.Ranges            (Range (..))
+import Data.Tree                     (Tree (..))
+import Text.Parsec.Error             (errorMessages,
+                                      showErrorMessages)
+import Text.Parsec.Prim              (parserFail)
+import Text.ParserCombinators.Parsec (GenParser, ParseError, Parser,
+                                      anyChar, between, char, digit,
+                                      eof, errorPos, letter,
+                                      lookAhead, many1, noneOf,
+                                      notFollowedBy, oneOf,
+                                      optionMaybe, sepBy1, string,
+                                      try, (<?>))
+
+import PostgREST.RangeQuery              (NonnegRange, allRange,
+                                          rangeGeq, rangeLimit,
+                                          rangeOffset, restrictRange)
+import PostgREST.SchemaCache.Identifiers (FieldName)
+
+import PostgREST.ApiRequest.Types (EmbedParam (..), EmbedPath, Field,
+                                   Filter (..), FtsOperator (..),
+                                   JoinType (..), JsonOperand (..),
+                                   JsonOperation (..), JsonPath,
+                                   ListVal, LogicOperator (..),
+                                   LogicTree (..), OpExpr (..),
+                                   Operation (..),
+                                   OrderDirection (..),
+                                   OrderNulls (..), OrderTerm (..),
+                                   QPError (..), SelectItem (..),
+                                   SimpleOperator (..), SingleVal,
+                                   TrileanVal (..))
+
+import Protolude hiding (try)
+
+
+-- $setup
+-- Setup for doctests
+-- >>> import Text.Pretty.Simple (pPrint)
+-- >>> deriving instance Show QPError
+-- >>> deriving instance Show TrileanVal
+-- >>> deriving instance Show FtsOperator
+-- >>> deriving instance Show SimpleOperator
+-- >>> deriving instance Show Operation
+-- >>> deriving instance Show OpExpr
+-- >>> deriving instance Show JsonOperand
+-- >>> deriving instance Show JsonOperation
+-- >>> deriving instance Show Filter
+-- >>> deriving instance Show JoinType
+-- >>> deriving instance Show SelectItem
+
+data QueryParams =
+  QueryParams
+    { qsCanonical      :: ByteString
+    -- ^ Canonical representation of the query params, sorted alphabetically
+    , qsParams         :: [(Text, Text)]
+    -- ^ Parameters for RPC calls
+    , qsRanges         :: HM.HashMap Text (Range Integer)
+    -- ^ Ranges derived from &limit and &offset params
+    , qsOrder          :: [(EmbedPath, [OrderTerm])]
+    -- ^ &order parameters for each level
+    , qsLogic          :: [(EmbedPath, LogicTree)]
+    -- ^ &and and &or parameters used for complex boolean logic
+    , qsColumns        :: Maybe (S.Set FieldName)
+    -- ^ &columns parameter and payload
+    , qsSelect         :: [Tree SelectItem]
+    -- ^ &select parameter used to shape the response
+    , qsFilters        :: [(EmbedPath, Filter)]
+    -- ^ Filters on the result from e.g. &id=e.10
+    , qsFiltersRoot    :: [Filter]
+    -- ^ Subset of the filters that apply on the root table. These are used on UPDATE/DELETE.
+    , qsFiltersNotRoot :: [(EmbedPath, Filter)]
+    -- ^ Subset of the filters that do not apply on the root table
+    , qsFilterFields   :: S.Set FieldName
+    -- ^ Set of fields that filters apply to
+    , qsOnConflict     :: Maybe [FieldName]
+    -- ^ &on_conflict parameter used to upsert on specific unique keys
+    }
+
+-- |
+-- Parse query parameters from a query string like "id=eq.1&select=name".
+--
+-- The canonical representation of the query string has parameters sorted alphabetically:
+--
+-- >>> qsCanonical <$> parse "a=1&c=3&b=2&d"
+-- Right "a=1&b=2&c=3&d="
+--
+-- 'select' is a reserved parameter that selects the fields to be returned:
+--
+-- >>> qsSelect <$> parse "select=name,location"
+-- Right [Node {rootLabel = SelectField {selField = ("name",[]), selCast = Nothing, selAlias = Nothing}, subForest = []},Node {rootLabel = SelectField {selField = ("location",[]), selCast = Nothing, selAlias = Nothing}, subForest = []}]
+--
+-- Filters are parameters whose value contains an operator, separated by a '.' from its value:
+--
+-- >>> qsFilters <$> parse "a.b=eq.0"
+-- Right [(["a"],Filter {field = ("b",[]), opExpr = OpExpr False (Op OpEqual "0")})]
+--
+-- If the operator specified in a filter does not exist, parsing the query string fails:
+--
+-- >>> qsFilters <$> parse "a.b=noop.0"
+-- Left (QPError "\"failed to parse filter (noop.0)\" (line 1, column 6)" "unknown single value operator noop")
+parse :: ByteString -> Either QPError QueryParams
+parse qs =
+  QueryParams
+    canonical
+    params
+    ranges
+    <$> pRequestOrder `traverse` order
+    <*> pRequestLogicTree `traverse` logic
+    <*> pRequestColumns columns
+    <*> pRequestSelect select
+    <*> pRequestFilter `traverse` filters
+    <*> (fmap snd <$> (pRequestFilter `traverse` filtersRoot))
+    <*> pRequestFilter `traverse` filtersNotRoot
+    <*> pure (S.fromList (fst <$> filters))
+    <*> pRequestOnConflict `traverse` onConflict
+  where
+    logic = filter (endingIn ["and", "or"] . fst) nonemptyParams
+    select = fromMaybe "*" $ lookupParam "select"
+    onConflict = lookupParam "on_conflict"
+    columns = lookupParam "columns"
+    order = filter (endingIn ["order"] . fst) nonemptyParams
+    limits = filter (endingIn ["limit"] . fst) nonemptyParams
+    -- Replace .offset ending with .limit to be able to match those params later in a map
+    offsets = first (replaceLast "limit") <$> filter (endingIn ["offset"] . fst) nonemptyParams
+    lookupParam :: Text -> Maybe Text
+    lookupParam needle = toS <$> join (L.lookup needle qParams)
+    nonemptyParams = mapMaybe (\(k, v) -> (k,) <$> v) qParams
+
+    qString = HTTP.parseQueryReplacePlus True qs
+
+    qParams = [(T.decodeUtf8 k, T.decodeUtf8 <$> v)|(k,v) <- qString]
+
+    canonical =
+      BS.pack $ HTTP.urlEncodeVars
+        . L.sortOn fst
+        . map (join (***) BS.unpack . second (fromMaybe mempty))
+        $ qString
+
+    endingIn:: [Text] -> Text -> Bool
+    endingIn xx key = lastWord `elem` xx
+      where lastWord = L.last $ T.split (== '.') key
+
+    (filters, params) = L.partition isParam filtersAndParams
+    isParam (k, v) = isEmbedPath k || hasOperator v || hasFtsOperator v
+
+    filtersAndParams = filter (isFilterOrParam . fst)  nonemptyParams
+    isFilterOrParam k = not (endingIn reservedEmbeddable k) && notElem k reserved
+    reserved = ["select", "columns", "on_conflict"]
+    reservedEmbeddable = ["order", "limit", "offset", "and", "or"]
+
+    (filtersNotRoot, filtersRoot) = L.partition isNotRoot filters
+    isNotRoot = flip T.isInfixOf "." . fst
+
+    -- TODO: These checks are redundant to the parsers, should use parsers to differentiate params
+    hasOperator val =
+      case T.splitOn "." val of
+        "not" : _ : _ -> True
+        "is" : _      -> True
+        "in" : _      -> True
+        x : _         -> isJust (operator x) || isJust (ftsOperator x)
+        _             -> False
+
+    hasFtsOperator val =
+      case T.splitOn "(" val of
+        x : _ : _ -> isJust $ ftsOperator x
+        _         -> False
+
+    isEmbedPath = T.isInfixOf "."
+    replaceLast x s = T.intercalate "." $ L.init (T.split (=='.') s) <> [x]
+
+    ranges :: HM.HashMap Text (Range Integer)
+    ranges = HM.unionWith f limitParams offsetParams
+      where
+        f rl ro = Range (BoundaryBelow o) (BoundaryAbove $ o + l - 1)
+          where
+            l = fromMaybe 0 $ rangeLimit rl
+            o = rangeOffset ro
+
+        limitParams =
+          HM.fromList [(k, restrictRange (readMaybe v) allRange) | (k,v) <- limits]
+
+        offsetParams =
+          HM.fromList [(k, maybe allRange rangeGeq (readMaybe v)) | (k,v) <- offsets]
+
+operator :: Text -> Maybe SimpleOperator
+operator = \case
+  "eq"     -> Just OpEqual
+  "gte"    -> Just OpGreaterThanEqual
+  "gt"     -> Just OpGreaterThan
+  "lte"    -> Just OpLessThanEqual
+  "lt"     -> Just OpLessThan
+  "neq"    -> Just OpNotEqual
+  "like"   -> Just OpLike
+  "ilike"  -> Just OpILike
+  "cs"     -> Just OpContains
+  "cd"     -> Just OpContained
+  "ov"     -> Just OpOverlap
+  "sl"     -> Just OpStrictlyLeft
+  "sr"     -> Just OpStrictlyRight
+  "nxr"    -> Just OpNotExtendsRight
+  "nxl"    -> Just OpNotExtendsLeft
+  "adj"    -> Just OpAdjacent
+  "match"  -> Just OpMatch
+  "imatch" -> Just OpIMatch
+  _        -> Nothing
+
+ftsOperator :: Text -> Maybe FtsOperator
+ftsOperator = \case
+  "fts"   -> Just FilterFts
+  "plfts" -> Just FilterFtsPlain
+  "phfts" -> Just FilterFtsPhrase
+  "wfts"  -> Just FilterFtsWebsearch
+  _       -> Nothing
+
+
+-- PARSERS
+
+
+pRequestSelect :: Text -> Either QPError [Tree SelectItem]
+pRequestSelect selStr =
+  mapError $ P.parse pFieldForest ("failed to parse select parameter (" <> toS selStr <> ")") (toS selStr)
+
+pRequestOnConflict :: Text -> Either QPError [FieldName]
+pRequestOnConflict oncStr =
+  mapError $ P.parse pColumns ("failed to parse on_conflict parameter (" <> toS oncStr <> ")") (toS oncStr)
+
+pRequestFilter :: (Text, Text) -> Either QPError (EmbedPath, Filter)
+pRequestFilter (k, v) = mapError $ (,) <$> path <*> (Filter <$> fld <*> oper)
+  where
+    treePath = P.parse pTreePath ("failed to parse tree path (" ++ toS k ++ ")") $ toS k
+    oper = P.parse (pOpExpr pSingleVal) ("failed to parse filter (" ++ toS v ++ ")") $ toS v
+    path = fst <$> treePath
+    fld = snd <$> treePath
+
+pRequestOrder :: (Text, Text) -> Either QPError (EmbedPath, [OrderTerm])
+pRequestOrder (k, v) = mapError $ (,) <$> path <*> ord'
+  where
+    treePath = P.parse pTreePath ("failed to parse tree path (" ++ toS k ++ ")") $ toS k
+    path = fst <$> treePath
+    ord' = P.parse pOrder ("failed to parse order (" ++ toS v ++ ")") $ toS v
+
+pRequestRange :: (Text, NonnegRange) -> Either QPError (EmbedPath, NonnegRange)
+pRequestRange (k, v) = mapError $ (,) <$> path <*> pure v
+  where
+    treePath = P.parse pTreePath ("failed to parse tree path (" ++ toS k ++ ")") $ toS k
+    path = fst <$> treePath
+
+pRequestLogicTree :: (Text, Text) -> Either QPError (EmbedPath, LogicTree)
+pRequestLogicTree (k, v) = mapError $ (,) <$> embedPath <*> logicTree
+  where
+    path = P.parse pLogicPath ("failed to parse logic path (" ++ toS k ++ ")") $ toS k
+    embedPath = fst <$> path
+    logicTree = do
+      op <- snd <$> path
+      -- Concat op and v to make pLogicTree argument regular,
+      -- in the form of "?and=and(.. , ..)" instead of "?and=(.. , ..)"
+      P.parse pLogicTree ("failed to parse logic tree (" ++ toS v ++ ")") $ toS (op <> v)
+
+pRequestColumns :: Maybe Text -> Either QPError (Maybe (S.Set FieldName))
+pRequestColumns colStr =
+  case colStr of
+    Just str ->
+      mapError $ Just . S.fromList <$> P.parse pColumns ("failed to parse columns parameter (" <> toS str <> ")") (toS str)
+    _ -> Right Nothing
+
+ws :: Parser Text
+ws = toS <$> many (oneOf " \t")
+
+lexeme :: Parser a -> Parser a
+lexeme p = ws *> p <* ws
+
+pTreePath :: Parser (EmbedPath, Field)
+pTreePath = do
+  p <- pFieldName `sepBy1` pDelimiter
+  jp <- P.option [] pJsonPath
+  return (init p, (last p, jp))
+
+-- |
+-- Parse select= into a Forest of SelectItems
+--
+-- >>> P.parse pFieldForest "" "id"
+-- Right [Node {rootLabel = SelectField {selField = ("id",[]), selCast = Nothing, selAlias = Nothing}, subForest = []}]
+--
+-- >>> P.parse pFieldForest "" "client(id)"
+-- Right [Node {rootLabel = SelectRelation {selRelation = "client", selAlias = Nothing, selHint = Nothing, selJoinType = Nothing}, subForest = [Node {rootLabel = SelectField {selField = ("id",[]), selCast = Nothing, selAlias = Nothing}, subForest = []}]}]
+--
+-- >>> P.parse pFieldForest "" "*,client(*,nested(*))"
+-- Right [Node {rootLabel = SelectField {selField = ("*",[]), selCast = Nothing, selAlias = Nothing}, subForest = []},Node {rootLabel = SelectRelation {selRelation = "client", selAlias = Nothing, selHint = Nothing, selJoinType = Nothing}, subForest = [Node {rootLabel = SelectField {selField = ("*",[]), selCast = Nothing, selAlias = Nothing}, subForest = []},Node {rootLabel = SelectRelation {selRelation = "nested", selAlias = Nothing, selHint = Nothing, selJoinType = Nothing}, subForest = [Node {rootLabel = SelectField {selField = ("*",[]), selCast = Nothing, selAlias = Nothing}, subForest = []}]}]}]
+--
+-- >>> P.parse pFieldForest "" "id,clients(name[])"
+-- Left (line 1, column 16):
+-- unexpected '['
+-- expecting letter, digit, "-", "!", "(", "->>", "->", "::", ")", "," or end of input
+pFieldForest :: Parser [Tree SelectItem]
+pFieldForest = pFieldTree `sepBy1` lexeme (char ',')
+  where
+    pFieldTree :: Parser (Tree SelectItem)
+    pFieldTree =  try (Node <$> pRelationSelect <*> between (char '(') (char ')') pFieldForest) <|>
+                  Node <$> pFieldSelect <*> pure []
+
+pStar :: Parser Text
+pStar = string "*" $> "*"
+
+-- |
+-- Parse field names
+--
+-- >>> P.parse pFieldName "" "identifier"
+-- Right "identifier"
+--
+-- >>> P.parse pFieldName "" "identifier with spaces"
+-- Right "identifier with spaces"
+--
+-- >>> P.parse pFieldName "" "identifier-with-dashes"
+-- Right "identifier-with-dashes"
+--
+-- >>> P.parse pFieldName "" "123"
+-- Right "123"
+--
+-- >>> P.parse pFieldName "" "_"
+-- Right "_"
+--
+-- >>> P.parse pFieldName "" "$"
+-- Right "$"
+--
+-- >>> P.parse pFieldName "" ":"
+-- Left (line 1, column 1):
+-- unexpected ":"
+-- expecting field name (* or [a..z0..9_$])
+--
+-- >>> P.parse pFieldName "" "\":\""
+-- Right ":"
+--
+-- >>> P.parse pFieldName "" " no leading or trailing spaces "
+-- Right "no leading or trailing spaces"
+--
+-- >>> P.parse pFieldName "" "\" leading and trailing spaces \""
+-- Right " leading and trailing spaces "
+pFieldName :: Parser Text
+pFieldName =
+  pQuotedValue <|>
+  T.intercalate "-" . map toS <$> (pIdentifier `sepBy1` dash) <?>
+  "field name (* or [a..z0..9_$])"
+  where
+    isDash :: GenParser Char st ()
+    isDash = try ( char '-' >> notFollowedBy (char '>') )
+    dash :: Parser Char
+    dash = isDash $> '-'
+
+-- |
+-- Parse json operators in select, order and filters
+--
+-- >>> P.parse pJsonPath "" "->text"
+-- Right [JArrow {jOp = JKey {jVal = "text"}}]
+--
+-- >>> P.parse pJsonPath "" "->1"
+-- Right [JArrow {jOp = JIdx {jVal = "+1"}}]
+--
+-- >>> P.parse pJsonPath "" "->>text"
+-- Right [J2Arrow {jOp = JKey {jVal = "text"}}]
+--
+-- >>> P.parse pJsonPath "" "->>1"
+-- Right [J2Arrow {jOp = JIdx {jVal = "+1"}}]
+--
+-- >>> P.parse pJsonPath "" "->0,other"
+-- Right [JArrow {jOp = JIdx {jVal = "+0"}}]
+--
+-- >>> P.parse pJsonPath "" "->0.desc"
+-- Right [JArrow {jOp = JIdx {jVal = "+0"}}]
+pJsonPath :: Parser JsonPath
+pJsonPath = many pJsonOperation
+  where
+    pJsonOperation :: Parser JsonOperation
+    pJsonOperation = pJsonArrow <*> pJsonOperand
+
+    pJsonArrow   =
+      try (string "->>" $> J2Arrow) <|>
+      try (string "->" $> JArrow)
+
+    pJsonOperand =
+      let pJKey = JKey . toS <$> pFieldName
+          pJIdx = JIdx . toS <$> ((:) <$> P.option '+' (char '-') <*> many1 digit) <* pEnd
+          pEnd = try (void $ lookAhead (string "->")) <|>
+                 try (void $ lookAhead (string "::")) <|>
+                 try (void $ lookAhead (string ".")) <|>
+                 try (void $ lookAhead (string ",")) <|>
+                 try eof in
+      try pJIdx <|> try pJKey
+
+pField :: Parser Field
+pField = lexeme $ (,) <$> pFieldName <*> P.option [] pJsonPath
+
+aliasSeparator :: Parser ()
+aliasSeparator = char ':' >> notFollowedBy (char ':')
+
+-- |
+-- Parse regular fields in select
+--
+-- >>> P.parse pRelationSelect "" "rel(*)"
+-- Right (SelectRelation {selRelation = "rel", selAlias = Nothing, selHint = Nothing, selJoinType = Nothing})
+--
+-- >>> P.parse pRelationSelect "" "alias:rel(*)"
+-- Right (SelectRelation {selRelation = "rel", selAlias = Just "alias", selHint = Nothing, selJoinType = Nothing})
+--
+-- >>> P.parse pRelationSelect "" "rel!hint(*)"
+-- Right (SelectRelation {selRelation = "rel", selAlias = Nothing, selHint = Just "hint", selJoinType = Nothing})
+--
+-- >>> P.parse pRelationSelect "" "rel!inner(*)"
+-- Right (SelectRelation {selRelation = "rel", selAlias = Nothing, selHint = Nothing, selJoinType = Just JTInner})
+--
+-- >>> P.parse pRelationSelect "" "rel!hint!inner(*)"
+-- Right (SelectRelation {selRelation = "rel", selAlias = Nothing, selHint = Just "hint", selJoinType = Just JTInner})
+--
+-- >>> P.parse pRelationSelect "" "alias:rel!inner!hint(*)"
+-- Right (SelectRelation {selRelation = "rel", selAlias = Just "alias", selHint = Just "hint", selJoinType = Just JTInner})
+--
+-- >>> P.parse pRelationSelect "" "rel->jsonpath(*)"
+-- Left (line 1, column 6):
+-- unexpected '>'
+--
+-- >>> P.parse pRelationSelect "" "rel->jsonpath!hint(*)"
+-- Left (line 1, column 6):
+-- unexpected '>'
+pRelationSelect :: Parser SelectItem
+pRelationSelect = lexeme $ try ( do
+    alias <- optionMaybe ( try(pFieldName <* aliasSeparator) )
+    name <- pFieldName
+    prm1 <- optionMaybe pEmbedParam
+    prm2 <- optionMaybe pEmbedParam
+    try (void $ lookAhead (string "("))
+    return $ SelectRelation name alias (embedParamHint prm1 <|> embedParamHint prm2) (embedParamJoin prm1 <|> embedParamJoin prm2)
+  )
+  where
+    pEmbedParam :: Parser EmbedParam
+    pEmbedParam =
+      char '!' *> (
+        try (string "left"  $> EPJoinType JTLeft)  <|>
+        try (string "inner" $> EPJoinType JTInner) <|>
+        try (EPHint <$> pFieldName))
+    embedParamHint prm = case prm of
+      Just (EPHint hint) -> Just hint
+      _                  -> Nothing
+    embedParamJoin prm = case prm of
+      Just (EPJoinType jt) -> Just jt
+      _                    -> Nothing
+
+-- |
+-- Parse regular fields in select
+--
+-- >>> P.parse pFieldSelect "" "name"
+-- Right (SelectField {selField = ("name",[]), selCast = Nothing, selAlias = Nothing})
+--
+-- >>> P.parse pFieldSelect "" "name->jsonpath"
+-- Right (SelectField {selField = ("name",[JArrow {jOp = JKey {jVal = "jsonpath"}}]), selCast = Nothing, selAlias = Nothing})
+--
+-- >>> P.parse pFieldSelect "" "name::cast"
+-- Right (SelectField {selField = ("name",[]), selCast = Just "cast", selAlias = Nothing})
+--
+-- >>> P.parse pFieldSelect "" "alias:name"
+-- Right (SelectField {selField = ("name",[]), selCast = Nothing, selAlias = Just "alias"})
+--
+-- >>> P.parse pFieldSelect "" "alias:name->jsonpath::cast"
+-- Right (SelectField {selField = ("name",[JArrow {jOp = JKey {jVal = "jsonpath"}}]), selCast = Just "cast", selAlias = Just "alias"})
+--
+-- >>> P.parse pFieldSelect "" "*"
+-- Right (SelectField {selField = ("*",[]), selCast = Nothing, selAlias = Nothing})
+--
+-- >>> P.parse pFieldSelect "" "name!hint"
+-- Left (line 1, column 5):
+-- unexpected '!'
+-- expecting letter, digit, "-", "->>", "->", "::", ")", "," or end of input
+--
+-- >>> P.parse pFieldSelect "" "*!hint"
+-- Left (line 1, column 2):
+-- unexpected '!'
+-- expecting ")", "," or end of input
+--
+-- >>> P.parse pFieldSelect "" "name::"
+-- Left (line 1, column 7):
+-- unexpected end of input
+-- expecting letter or digit
+pFieldSelect :: Parser SelectItem
+pFieldSelect = lexeme $
+  try (
+    do
+      alias <- optionMaybe ( try(pFieldName <* aliasSeparator) )
+      fld <- pField
+      cast' <- optionMaybe (string "::" *> pIdentifier)
+      pEnd
+      return $ SelectField fld (toS <$> cast') alias
+  )
+  <|> do
+    s <- pStar
+    pEnd
+    return $ SelectField (s, []) Nothing Nothing
+  where
+    pEnd = try (void $ lookAhead (string ")")) <|>
+           try (void $ lookAhead (string ",")) <|>
+           try eof
+
+-- |
+-- Parse operator expression used in horizontal filtering
+--
+-- >>> P.parse (pOpExpr pSingleVal) "" "fts().value"
+-- Left (line 1, column 7):
+-- unknown single value operator fts()
+pOpExpr :: Parser SingleVal -> Parser OpExpr
+pOpExpr pSVal = try ( string "not" *> pDelimiter *> (OpExpr True <$> pOperation)) <|> OpExpr False <$> pOperation
+  where
+    pOperation :: Parser Operation
+    pOperation = pIn <|> pIs <|> try pFts <|> pOp <?> "operator (eq, gt, ...)"
+
+    pIn = In <$> (try (string "in" *> pDelimiter) *> pListVal)
+    pIs = Is <$> (try (string "is" *> pDelimiter) *> pTriVal)
+
+    pOp = do
+      opStr <- try (P.manyTill anyChar (try pDelimiter))
+      op <- parseMaybe ("unknown single value operator " <> opStr) . operator $ toS opStr
+      Op op <$> pSVal
+
+    pTriVal = try (ciString "null"    $> TriNull)
+          <|> try (ciString "unknown" $> TriUnknown)
+          <|> try (ciString "true"    $> TriTrue)
+          <|> try (ciString "false"   $> TriFalse)
+          <?> "null or trilean value (unknown, true, false)"
+
+    pFts = do
+      opStr <- try (P.many (noneOf ".("))
+      op <- parseMaybe ("unknown fts operator " <> opStr) . ftsOperator $ toS opStr
+      lang <- optionMaybe $ try (between (char '(') (char ')') pIdentifier)
+      pDelimiter >> Fts op (toS <$> lang) <$> pSVal
+
+    parseMaybe :: [Char] -> Maybe a -> Parser a
+    parseMaybe err Nothing = parserFail err
+    parseMaybe _ (Just x)  = pure x
+
+    -- case insensitive char and string
+    ciChar :: Char -> GenParser Char state Char
+    ciChar c = char c <|> char (toUpper c)
+    ciString :: [Char] -> GenParser Char state [Char]
+    ciString = traverse ciChar
+
+pSingleVal :: Parser SingleVal
+pSingleVal = toS <$> many anyChar
+
+pListVal :: Parser ListVal
+pListVal = lexeme (char '(') *> pListElement `sepBy1` char ',' <* lexeme (char ')')
+
+pListElement :: Parser Text
+pListElement = try (pQuotedValue <* notFollowedBy (noneOf ",)")) <|> (toS <$> many (noneOf ",)"))
+
+pQuotedValue :: Parser Text
+pQuotedValue = toS <$> (char '"' *> many pCharsOrSlashed <* char '"')
+  where
+    pCharsOrSlashed = noneOf "\\\"" <|> (char '\\' *> anyChar)
+
+pDelimiter :: Parser Char
+pDelimiter = char '.' <?> "delimiter (.)"
+
+pOrder :: Parser [OrderTerm]
+pOrder = lexeme pOrderTerm `sepBy1` char ','
+
+pOrderTerm :: Parser OrderTerm
+pOrderTerm = do
+  fld <- pField
+  dir <- optionMaybe $
+         try (pDelimiter *> string "asc" $> OrderAsc) <|>
+         try (pDelimiter *> string "desc" $> OrderDesc)
+  nls <- optionMaybe pNulls <* pEnd <|>
+         pEnd $> Nothing
+  return $ OrderTerm fld dir nls
+  where
+    pNulls = try (pDelimiter *> string "nullsfirst" $> OrderNullsFirst) <|>
+             try (pDelimiter *> string "nullslast"  $> OrderNullsLast)
+    pEnd = try (void $ lookAhead (char ',')) <|>
+           try eof
+
+pLogicTree :: Parser LogicTree
+pLogicTree = Stmnt <$> try pLogicFilter
+             <|> Expr <$> pNot <*> pLogicOp <*> (lexeme (char '(') *> pLogicTree `sepBy1` lexeme (char ',') <* lexeme (char ')'))
+  where
+    pLogicFilter :: Parser Filter
+    pLogicFilter = Filter <$> pField <* pDelimiter <*> pOpExpr pLogicSingleVal
+    pNot :: Parser Bool
+    pNot = try (string "not" *> pDelimiter $> True)
+           <|> pure False
+           <?> "negation operator (not)"
+    pLogicOp :: Parser LogicOperator
+    pLogicOp = try (string "and" $> And)
+               <|> string "or" $> Or
+               <?> "logic operator (and, or)"
+
+pLogicSingleVal :: Parser SingleVal
+pLogicSingleVal = try (pQuotedValue <* notFollowedBy (noneOf ",)")) <|> try pPgArray <|> (toS <$> many (noneOf ",)"))
+  where
+    pPgArray :: Parser Text
+    pPgArray =  do
+      a <- string "{"
+      b <- many (noneOf "{}")
+      c <- string "}"
+      pure (toS $ a ++ b ++ c)
+
+pLogicPath :: Parser (EmbedPath, Text)
+pLogicPath = do
+  path <- pFieldName `sepBy1` pDelimiter
+  let op = last path
+      notOp = "not." <> op
+  return (filter (/= "not") (init path), if "not" `elem` path then notOp else op)
+
+pColumns :: Parser [FieldName]
+pColumns = pFieldName `sepBy1` lexeme (char ',')
+
+pIdentifier :: Parser Text
+pIdentifier = T.strip . toS <$> many1 pIdentifierChar
+
+pIdentifierChar :: Parser Char
+pIdentifierChar = letter <|> digit <|> oneOf "_ $"
+
+mapError :: Either ParseError a -> Either QPError a
+mapError = mapLeft translateError
+  where
+    translateError e =
+      QPError message details
+      where
+        message = show $ errorPos e
+        details = T.strip $ T.replace "\n" " " $ toS
+           $ showErrorMessages "or" "unknown parse error" "expecting" "unexpected" "end of input" (errorMessages e)
@@ -0,0 +1,220 @@
+{-# LANGUAGE DuplicateRecordFields #-}
+module PostgREST.ApiRequest.Types
+  ( Alias
+  , Cast
+  , Depth
+  , EmbedParam(..)
+  , ApiRequestError(..)
+  , EmbedPath
+  , Field
+  , Filter(..)
+  , Hint
+  , JoinType(..)
+  , JsonOperand(..)
+  , JsonOperation(..)
+  , JsonPath
+  , ListVal
+  , LogicOperator(..)
+  , LogicTree(..)
+  , NodeName
+  , OpExpr(..)
+  , Operation (..)
+  , OrderDirection(..)
+  , OrderNulls(..)
+  , OrderTerm(..)
+  , QPError(..)
+  , RangeError(..)
+  , SingleVal
+  , TrileanVal(..)
+  , SimpleOperator(..)
+  , FtsOperator(..)
+  , SelectItem(..)
+  ) where
+
+import PostgREST.MediaType                (MediaType (..))
+import PostgREST.SchemaCache.Identifiers  (FieldName,
+                                           QualifiedIdentifier)
+import PostgREST.SchemaCache.Proc         (ProcDescription (..))
+import PostgREST.SchemaCache.Relationship (Relationship,
+                                           RelationshipsMap)
+
+import Protolude
+
+-- | The select value in `/tbl?select=alias:field::cast`
+data SelectItem
+  = SelectField
+    { selField :: Field
+    , selCast  :: Maybe Cast
+    , selAlias :: Maybe Alias
+    }
+  | SelectRelation
+    { selRelation :: FieldName
+    , selAlias    :: Maybe Alias
+    , selHint     :: Maybe Hint
+    , selJoinType :: Maybe JoinType
+    }
+  deriving (Eq)
+
+data ApiRequestError
+  = AmbiguousRelBetween Text Text [Relationship]
+  | AmbiguousRpc [ProcDescription]
+  | BinaryFieldError MediaType
+  | MediaTypeError [ByteString]
+  | InvalidBody ByteString
+  | InvalidFilters
+  | InvalidRange RangeError
+  | InvalidRpcMethod ByteString
+  | LimitNoOrderError
+  | NotFound
+  | NoRelBetween Text Text (Maybe Text) Text RelationshipsMap
+  | NoRpc Text Text [Text] Bool MediaType Bool [QualifiedIdentifier] [ProcDescription]
+  | NotEmbedded Text
+  | ParseRequestError Text Text
+  | PutRangeNotAllowedError
+  | QueryParamError QPError
+  | UnacceptableSchema [Text]
+  | UnsupportedMethod ByteString
+
+data QPError = QPError Text Text
+data RangeError
+  = NegativeLimit
+  | LowerGTUpper
+  | OutOfBounds Text Text
+
+type NodeName = Text
+type Depth = Integer
+
+data OrderTerm = OrderTerm
+  { otTerm      :: Field
+  , otDirection :: Maybe OrderDirection
+  , otNullOrder :: Maybe OrderNulls
+  }
+  deriving (Eq)
+
+data OrderDirection
+  = OrderAsc
+  | OrderDesc
+  deriving (Eq)
+
+data OrderNulls
+  = OrderNullsFirst
+  | OrderNullsLast
+  deriving (Eq)
+
+type Field = (FieldName, JsonPath)
+type Cast = Text
+type Alias = Text
+type Hint = Text
+
+data EmbedParam
+  -- | Disambiguates an embedding operation when there's multiple relationships
+  -- between two tables. Can be the name of a foreign key constraint, column
+  -- name or the junction in an m2m relationship.
+  = EPHint Hint
+  | EPJoinType JoinType
+
+data JoinType
+  = JTInner
+  | JTLeft
+  deriving Eq
+
+-- | Path of the embedded levels, e.g "clients.projects.name=eq.." gives Path
+-- ["clients", "projects"]
+type EmbedPath = [Text]
+
+-- | Json path operations as specified in
+-- https://www.postgresql.org/docs/current/static/functions-json.html
+type JsonPath = [JsonOperation]
+
+-- | Represents the single arrow `->` or double arrow `->>` operators
+data JsonOperation
+  = JArrow { jOp :: JsonOperand }
+  | J2Arrow { jOp :: JsonOperand }
+  deriving (Eq)
+
+-- | Represents the key(`->'key'`) or index(`->'1`::int`), the index is Text
+-- because we reuse our escaping functons and let pg do the casting with
+-- '1'::int
+data JsonOperand
+  = JKey { jVal :: Text }
+  | JIdx { jVal :: Text }
+  deriving (Eq)
+
+-- | Boolean logic expression tree e.g. "and(name.eq.N,or(id.eq.1,id.eq.2))" is:
+--
+--            And
+--           /   \
+--  name.eq.N     Or
+--               /  \
+--         id.eq.1   id.eq.2
+data LogicTree
+  = Expr Bool LogicOperator [LogicTree]
+  | Stmnt Filter
+  deriving (Eq)
+
+data LogicOperator
+  = And
+  | Or
+  deriving Eq
+
+data Filter = Filter
+  { field  :: Field
+  , opExpr :: OpExpr
+  }
+  deriving (Eq)
+
+data OpExpr =
+  OpExpr Bool Operation
+  deriving (Eq)
+
+data Operation
+  = Op SimpleOperator SingleVal
+  | In ListVal
+  | Is TrileanVal
+  | Fts FtsOperator (Maybe Language) SingleVal
+  deriving (Eq)
+
+type Language = Text
+
+-- | Represents a single value in a filter, e.g. id=eq.singleval
+type SingleVal = Text
+
+-- | Represents a list value in a filter, e.g. id=in.(val1,val2,val3)
+type ListVal = [Text]
+
+-- | Three-valued logic values
+data TrileanVal
+  = TriTrue
+  | TriFalse
+  | TriNull
+  | TriUnknown
+  deriving Eq
+
+data SimpleOperator
+  = OpEqual
+  | OpGreaterThanEqual
+  | OpGreaterThan
+  | OpLessThanEqual
+  | OpLessThan
+  | OpNotEqual
+  | OpLike
+  | OpILike
+  | OpContains
+  | OpContained
+  | OpOverlap
+  | OpStrictlyLeft
+  | OpStrictlyRight
+  | OpNotExtendsRight
+  | OpNotExtendsLeft
+  | OpAdjacent
+  | OpMatch
+  | OpIMatch
+  deriving Eq
+
+-- | Operators for full text search operators
+data FtsOperator
+  = FilterFts
+  | FilterFtsPlain
+  | FilterFtsPhrase
+  | FilterFtsWebsearch
+  deriving Eq
@@ -9,6 +9,7 @@ Some of its functionality includes:
 - Producing HTTP Headers according to RFCs.
 - Content Negotiation
 -}
+{-# LANGUAGE LambdaCase      #-}
 {-# LANGUAGE RecordWildCards #-}
 module PostgREST.App
  ( SignalHandlerInstaller
@@ -17,102 +18,62 @@ module PostgREST.App
  , run
  ) where

+
 import Control.Monad.Except     (liftEither)
-import Data.Either.Combinators  (mapLeft)
-import Data.List                (union)
+import Data.Either.Combinators  (mapLeft, whenLeft)
+import Data.Maybe               (fromJust)
 import Data.String              (IsString (..))
-import Data.Time.Clock          (UTCTime)
 import Network.Wai.Handler.Warp (defaultSettings, setHost, setPort,
                                 setServerName)
 import System.Posix.Types       (FileMode)

-import qualified Data.ByteString.Char8           as BS
-import qualified Data.ByteString.Lazy            as LBS
-import qualified Data.HashMap.Strict             as M
-import qualified Data.Set                        as S
-import qualified Hasql.DynamicStatements.Snippet as SQL
-import qualified Hasql.Pool                      as SQL
-import qualified Hasql.Transaction               as SQL
-import qualified Hasql.Transaction.Sessions      as SQL
-import qualified Network.HTTP.Types.Header       as HTTP
-import qualified Network.HTTP.Types.Status       as HTTP
-import qualified Network.HTTP.Types.URI          as HTTP
-import qualified Network.Wai                     as Wai
-import qualified Network.Wai.Handler.Warp        as Warp
+import qualified Hasql.Pool                 as SQL
+import qualified Hasql.Transaction.Sessions as SQL
+import qualified Network.Wai                as Wai
+import qualified Network.Wai.Handler.Warp   as Warp

-import qualified PostgREST.AppState                 as AppState
-import qualified PostgREST.Auth                     as Auth
-import qualified PostgREST.DbStructure              as DbStructure
-import qualified PostgREST.Error                    as Error
-import qualified PostgREST.Middleware               as Middleware
-import qualified PostgREST.OpenAPI                  as OpenAPI
-import qualified PostgREST.Query.QueryBuilder       as QueryBuilder
-import qualified PostgREST.Query.Statements         as Statements
-import qualified PostgREST.RangeQuery               as RangeQuery
-import qualified PostgREST.Request.ApiRequest       as ApiRequest
-import qualified PostgREST.Request.DbRequestBuilder as ReqBuilder
+import qualified PostgREST.ApiRequest       as ApiRequest
+import qualified PostgREST.ApiRequest.Types as ApiRequestTypes
+import qualified PostgREST.AppState         as AppState
+import qualified PostgREST.Auth             as Auth
+import qualified PostgREST.Cors             as Cors
+import qualified PostgREST.Error            as Error
+import qualified PostgREST.Logger           as Logger
+import qualified PostgREST.Plan             as Plan
+import qualified PostgREST.Query            as Query
+import qualified PostgREST.Response         as Response
+import qualified PostgREST.Workers          as Workers

-import PostgREST.AppState                (AppState)
-import PostgREST.Config                  (AppConfig (..),
-                                          LogLevel (..),
-                                          OpenAPIMode (..))
-import PostgREST.Config.PgVersion        (PgVersion (..))
-import PostgREST.ContentType             (ContentType (..))
-import PostgREST.DbStructure             (DbStructure (..),
-                                          tablePKCols)
-import PostgREST.DbStructure.Identifiers (FieldName,
-                                          QualifiedIdentifier (..),
-                                          Schema)
-import PostgREST.DbStructure.Proc        (ProcDescription (..),
-                                          ProcVolatility (..))
-import PostgREST.DbStructure.Table       (Table (..))
-import PostgREST.Error                   (Error)
-import PostgREST.GucHeader               (GucHeader,
-                                          addHeadersIfNotIncluded,
-                                          unwrapGucHeader)
-import PostgREST.Request.ApiRequest      (Action (..),
-                                          ApiRequest (..),
-                                          InvokeMethod (..),
-                                          Target (..))
-import PostgREST.Request.Preferences     (PreferCount (..),
-                                          PreferParameters (..),
-                                          PreferRepresentation (..),
-                                          toAppliedHeader)
-import PostgREST.Request.Types           (ReadRequest, fstFieldNames)
-import PostgREST.Version                 (prettyVersion)
-import PostgREST.Workers                 (connectionWorker, listener)
-
-import qualified PostgREST.ContentType      as ContentType
-import qualified PostgREST.DbStructure.Proc as Proc
+import PostgREST.ApiRequest       (Action (..), ApiRequest (..),
+                                   Mutation (..), Target (..))
+import PostgREST.AppState         (AppState)
+import PostgREST.Auth             (AuthResult (..))
+import PostgREST.Config           (AppConfig (..), LogLevel (..))
+import PostgREST.Config.PgVersion (PgVersion (..))
+import PostgREST.Error            (Error)
+import PostgREST.Query            (DbHandler)
+import PostgREST.SchemaCache      (SchemaCache (..))
+import PostgREST.Version          (prettyVersion)

 import Protolude hiding (Handler)

-
-data RequestContext = RequestContext
-  { ctxConfig      :: AppConfig
-  , ctxDbStructure :: DbStructure
-  , ctxApiRequest  :: ApiRequest
-  , ctxPgVersion   :: PgVersion
-  }
-
 type Handler = ExceptT Error

-type DbHandler = Handler SQL.Transaction
-
 type SignalHandlerInstaller = AppState -> IO()

 type SocketRunner = Warp.Settings -> Wai.Application -> FileMode -> FilePath -> IO()

-
 run :: SignalHandlerInstaller -> Maybe SocketRunner -> AppState -> IO ()
 run installHandlers maybeRunWithSocket appState = do
  conf@AppConfig{..} <- AppState.getConfig appState
-  connectionWorker appState -- Loads the initial DbStructure
+  Workers.connectionWorker appState -- Loads the initial SchemaCache
  installHandlers appState
  -- reload schema cache + config on NOTIFY
-  when configDbChannelEnabled $ listener appState
+  Workers.runListener conf appState

-  let app = postgrest configLogLevel appState (connectionWorker appState)
+  Workers.runAdmin conf appState $ serverSettings conf
+
+  let app = postgrest configLogLevel appState (Workers.connectionWorker appState)

  case configServerUnixSocket of
    Just socket ->
@@ -122,7 +83,7 @@ run installHandlers maybeRunWithSocket appState = do
          AppState.logWithZTime appState $ "Listening on unix socket " <> show socket
          runWithSocket (serverSettings conf) app configServerUnixSocketMode socket
        Nothing ->
-          panic "Cannot run with socket on non-unix plattforms."
+          panic "Cannot run with unix socket on non-unix platforms."
    Nothing ->
      do
        AppState.logWithZTime appState $ "Listening on port " <> show configServerPort
@@ -137,475 +98,123 @@ serverSettings AppConfig{..} =

 -- | PostgREST application
 postgrest :: LogLevel -> AppState.AppState -> IO () -> Wai.Application
-postgrest logLev appState connWorker =
-  Middleware.pgrstMiddleware logLev $
-    \req respond -> do
-      time <- AppState.getTime appState
-      conf <- AppState.getConfig appState
-      maybeDbStructure <- AppState.getDbStructure appState
-      pgVer <- AppState.getPgVersion appState
-      jsonDbS <- AppState.getJsonDbS appState
+postgrest logLevel appState connWorker =
+  Cors.middleware .
+  Auth.middleware appState .
+  Logger.middleware logLevel $
+    -- fromJust can be used, because the auth middleware will **always** add
+    -- some AuthResult to the vault.
+    \req respond -> case fromJust $ Auth.getResult req of
+      Left err -> respond $ Error.errorResponseFor err
+      Right authResult -> do
+        conf <- AppState.getConfig appState
+        maybeSchemaCache <- AppState.getSchemaCache appState
+        pgVer <- AppState.getPgVersion appState
+        jsonDbS <- AppState.getJsonDbS appState

-      let
-        eitherResponse :: IO (Either Error Wai.Response)
-        eitherResponse =
-          runExceptT $ postgrestResponse conf maybeDbStructure jsonDbS pgVer (AppState.getPool appState) time req
+        let
+          eitherResponse :: IO (Either Error Wai.Response)
+          eitherResponse =
+            runExceptT $ postgrestResponse appState conf maybeSchemaCache jsonDbS pgVer authResult req

-      response <- either Error.errorResponseFor identity <$> eitherResponse
-      -- Launch the connWorker when the connection is down.  The postgrest
-      -- function can respond successfully (with a stale schema cache) before
-      -- the connWorker is done.
-      let isPGAway = Wai.responseStatus response == HTTP.status503
-      when isPGAway connWorker
-      resp <- addRetryHint isPGAway appState response
-      respond resp
-
-addRetryHint :: Bool -> AppState -> Wai.Response -> IO Wai.Response
-addRetryHint shouldAdd appState response = do
-  delay <- AppState.getRetryNextIn appState
-  let h = ("Retry-After", BS.pack $ show delay)
-  return $ Wai.mapResponseHeaders (\hs -> if shouldAdd then h:hs else hs) response
+        response <- either Error.errorResponseFor identity <$> eitherResponse
+        -- Launch the connWorker when the connection is down.  The postgrest
+        -- function can respond successfully (with a stale schema cache) before
+        -- the connWorker is done.
+        when (Response.isServiceUnavailable response) connWorker
+        resp <- do
+          delay <- AppState.getRetryNextIn appState
+          return $ Response.addRetryHint delay response
+        respond resp

 postgrestResponse
-  :: AppConfig
-  -> Maybe DbStructure
+  :: AppState.AppState
+  -> AppConfig
+  -> Maybe SchemaCache
  -> ByteString
  -> PgVersion
-  -> SQL.Pool
-  -> UTCTime
+  -> AuthResult
  -> Wai.Request
  -> Handler IO Wai.Response
-postgrestResponse conf maybeDbStructure jsonDbS pgVer pool time req = do
+postgrestResponse appState conf@AppConfig{..} maybeSchemaCache jsonDbS pgVer authResult@AuthResult{..} req = do
+  sCache <-
+    case maybeSchemaCache of
+      Just sCache ->
+        return sCache
+      Nothing ->
+        throwError Error.NoSchemaCacheError
+
  body <- lift $ Wai.strictRequestBody req

-  dbStructure <-
-    case maybeDbStructure of
-      Just dbStructure ->
-        return dbStructure
-      Nothing ->
-        throwError Error.ConnectionLostError
-
-  apiRequest@ApiRequest{..} <-
+  apiRequest <-
    liftEither . mapLeft Error.ApiRequestError $
-      ApiRequest.userApiRequest conf dbStructure req body
+      ApiRequest.userApiRequest conf sCache req body

-  -- The JWT must be checked before touching the db
-  jwtClaims <- Auth.jwtClaims conf (toUtf8Lazy iJWT) time
+  Response.optionalRollback conf apiRequest $
+    handleRequest authResult conf appState (Query.txMode apiRequest) (Just authRole /= configDbAnonRole) configDbPreparedStatements jsonDbS pgVer apiRequest sCache

-  let
-    handleReq apiReq =
-      handleRequest $ RequestContext conf dbStructure apiReq pgVer
-
-  runDbHandler pool (txMode apiRequest) jwtClaims (configDbPreparedStatements conf) .
-    Middleware.optionalRollback conf apiRequest $
-      Middleware.runPgLocals conf jwtClaims handleReq apiRequest jsonDbS pgVer
-
-runDbHandler :: SQL.Pool -> SQL.Mode -> Auth.JWTClaims -> Bool -> DbHandler a -> Handler IO a
-runDbHandler pool mode jwtClaims prepared handler = do
-  dbResp <-
-    let transaction = if prepared then SQL.transaction else SQL.unpreparedTransaction in
-    lift . SQL.use pool . transaction SQL.ReadCommitted mode $ runExceptT handler
+runDbHandler :: AppState.AppState -> SQL.Mode -> Bool -> Bool -> DbHandler b -> Handler IO b
+runDbHandler appState mode authenticated prepared handler = do
+  dbResp <- lift $ do
+    let transaction = if prepared then SQL.transaction else SQL.unpreparedTransaction
+    res <- AppState.usePool appState . transaction SQL.ReadCommitted mode $ runExceptT handler
+    whenLeft res (\case
+      SQL.AcquisitionTimeoutUsageError -> AppState.debounceLogAcquisitionTimeout appState -- this can happen rapidly for many requests, so we debounce
+      _ -> pure ())
+    return res

  resp <-
    liftEither . mapLeft Error.PgErr $
-      mapLeft (Error.PgError $ Auth.containsRole jwtClaims) dbResp
+      mapLeft (Error.PgError authenticated) dbResp

  liftEither resp

-handleRequest :: RequestContext -> DbHandler Wai.Response
-handleRequest context@(RequestContext _ _ ApiRequest{..} _) =
+handleRequest :: AuthResult -> AppConfig -> AppState.AppState -> SQL.Mode -> Bool -> Bool -> ByteString -> PgVersion -> ApiRequest -> SchemaCache -> Handler IO Wai.Response
+handleRequest AuthResult{..} conf appState mode authenticated prepared jsonDbS pgVer apiReq@ApiRequest{..} sCache =
  case (iAction, iTarget) of
-    (ActionRead headersOnly, TargetIdent identifier) ->
-      handleRead headersOnly identifier context
-    (ActionCreate, TargetIdent identifier) ->
-      handleCreate identifier context
-    (ActionUpdate, TargetIdent identifier) ->
-      handleUpdate identifier context
-    (ActionSingleUpsert, TargetIdent identifier) ->
-      handleSingleUpsert identifier context
-    (ActionDelete, TargetIdent identifier) ->
-      handleDelete identifier context
-    (ActionInfo, TargetIdent identifier) ->
-      handleInfo identifier context
-    (ActionInvoke invMethod, TargetProc proc _) ->
-      handleInvoke invMethod proc context
-    (ActionInspect headersOnly, TargetDefaultSpec tSchema) ->
-      handleOpenApi headersOnly tSchema context
-    _ ->
-      throwError Error.NotFound
+    (ActionRead headersOnly, TargetIdent identifier) -> do
+      rPlan <- liftEither $ Plan.readPlan identifier conf sCache apiReq
+      resultSet <- runQuery $ Query.readQuery rPlan conf apiReq
+      return $ Response.readResponse headersOnly identifier apiReq resultSet

-handleRead :: Bool -> QualifiedIdentifier -> RequestContext -> DbHandler Wai.Response
-handleRead headersOnly identifier context@RequestContext{..} = do
-  req <- readRequest identifier context
-  bField <- binaryField context req
+    (ActionMutate MutationCreate, TargetIdent identifier) -> do
+      mrPlan <- liftEither $ Plan.mutateReadPlan MutationCreate apiReq identifier conf sCache
+      resultSet <- runQuery $ Query.createQuery mrPlan apiReq conf
+      return $ Response.createResponse identifier mrPlan apiReq resultSet

-  let
-    ApiRequest{..} = ctxApiRequest
-    AppConfig{..} = ctxConfig
-    countQuery = QueryBuilder.readRequestToCountQuery req
+    (ActionMutate MutationUpdate, TargetIdent identifier) -> do
+      mrPlan <- liftEither $ Plan.mutateReadPlan MutationUpdate apiReq identifier conf sCache
+      resultSet <- runQuery $ Query.updateQuery mrPlan apiReq conf
+      return $ Response.updateResponse apiReq resultSet

-  (tableTotal, queryTotal, _ , body, gucHeaders, gucStatus) <-
-    lift . SQL.statement mempty $
-      Statements.createReadStatement
-        (QueryBuilder.readRequestToQuery req)
-        (if iPreferCount == Just EstimatedCount then
-           -- LIMIT maxRows + 1 so we can determine below that maxRows was surpassed
-           QueryBuilder.limitedQuery countQuery ((+ 1) <$> configDbMaxRows)
-         else
-           countQuery
-        )
-        (iAcceptContentType == CTSingularJSON)
-        (shouldCount iPreferCount)
-        (iAcceptContentType == CTTextCSV)
-        bField
-        configDbPreparedStatements
+    (ActionMutate MutationSingleUpsert, TargetIdent identifier) -> do
+      mrPlan <- liftEither $ Plan.mutateReadPlan MutationSingleUpsert apiReq identifier conf sCache
+      resultSet <- runQuery $ Query.singleUpsertQuery mrPlan apiReq conf
+      return $ Response.singleUpsertResponse apiReq resultSet

-  total <- readTotal ctxConfig ctxApiRequest tableTotal countQuery
-  response <- liftEither $ gucResponse <$> gucStatus <*> gucHeaders
+    (ActionMutate MutationDelete, TargetIdent identifier) -> do
+      mrPlan <- liftEither $ Plan.mutateReadPlan MutationDelete apiReq identifier conf sCache
+      resultSet <- runQuery $ Query.deleteQuery mrPlan apiReq conf
+      return $ Response.deleteResponse apiReq resultSet

-  let
-    (status, contentRange) = RangeQuery.rangeStatusHeader iTopLevelRange queryTotal total
-    headers =
-      [ contentRange
-      , ( "Content-Location"
-        , "/"
-            <> toUtf8 (qiName identifier)
-            <> if BS.null iCanonicalQS then mempty else "?" <> iCanonicalQS
-        )
-      ]
-      ++ contentTypeHeaders context
+    (ActionInvoke invMethod, TargetProc proc _) -> do
+      cPlan <- liftEither $ Plan.callReadPlan proc conf sCache apiReq
+      resultSet <- runQuery $ Query.invokeQuery proc cPlan apiReq conf
+      return $ Response.invokeResponse invMethod proc apiReq resultSet

-  failNotSingular iAcceptContentType queryTotal . response status headers $
-    if headersOnly then mempty else LBS.fromStrict body
+    (ActionInspect headersOnly, TargetDefaultSpec tSchema) -> do
+      oaiResult <- runQuery $ Query.openApiQuery sCache pgVer conf tSchema
+      return $ Response.openApiResponse headersOnly oaiResult conf sCache iSchema iNegotiatedByProfile

-readTotal :: AppConfig -> ApiRequest -> Maybe Int64 -> SQL.Snippet -> DbHandler (Maybe Int64)
-readTotal AppConfig{..} ApiRequest{..} tableTotal countQuery =
-  case iPreferCount of
-    Just PlannedCount ->
-      explain
-    Just EstimatedCount ->
-      if tableTotal > (fromIntegral <$> configDbMaxRows) then
-        max tableTotal <$> explain
-      else
-        return tableTotal
-    _ ->
-      return tableTotal
-  where
-    explain =
-      lift . SQL.statement mempty . Statements.createExplainStatement countQuery $
-        configDbPreparedStatements
-
-handleCreate :: QualifiedIdentifier -> RequestContext -> DbHandler Wai.Response
-handleCreate identifier@QualifiedIdentifier{..} context@RequestContext{..} = do
-  let
-    ApiRequest{..} = ctxApiRequest
-    pkCols = tablePKCols ctxDbStructure qiSchema qiName
-
-  WriteQueryResult{..} <- writeQuery identifier True pkCols context
-
-  let
-    response = gucResponse resGucStatus resGucHeaders
-    headers =
-      catMaybes
-        [ if null resFields then
-            Nothing
-          else
-            Just
-              ( HTTP.hLocation
-              , "/"
-                  <> toUtf8 qiName
-                  <> HTTP.renderSimpleQuery True (splitKeyValue <$> resFields)
-              )
-        , Just . RangeQuery.contentRangeH 1 0 $
-            if shouldCount iPreferCount then Just resQueryTotal else Nothing
-        , if null pkCols && isNothing iOnConflict then
-            Nothing
-          else
-            toAppliedHeader <$> iPreferResolution
-        ]
-
-  failNotSingular iAcceptContentType resQueryTotal $
-    if iPreferRepresentation == Full then
-      response HTTP.status201 (headers ++ contentTypeHeaders context) (LBS.fromStrict resBody)
-    else
-      response HTTP.status201 headers mempty
-
-handleUpdate :: QualifiedIdentifier -> RequestContext -> DbHandler Wai.Response
-handleUpdate identifier context@(RequestContext _ _ ApiRequest{..} _) = do
-  WriteQueryResult{..} <- writeQuery identifier False mempty context
-
-  let
-    response = gucResponse resGucStatus resGucHeaders
-    fullRepr = iPreferRepresentation == Full
-    updateIsNoOp = S.null iColumns
-    status
-      | resQueryTotal == 0 && not updateIsNoOp = HTTP.status404
-      | fullRepr = HTTP.status200
-      | otherwise = HTTP.status204
-    contentRangeHeader =
-      RangeQuery.contentRangeH 0 (resQueryTotal - 1) $
-        if shouldCount iPreferCount then Just resQueryTotal else Nothing
-
-  failNotSingular iAcceptContentType resQueryTotal $
-    if fullRepr then
-      response status (contentTypeHeaders context ++ [contentRangeHeader]) (LBS.fromStrict resBody)
-    else
-      response status [contentRangeHeader] mempty
-
-handleSingleUpsert :: QualifiedIdentifier -> RequestContext-> DbHandler Wai.Response
-handleSingleUpsert identifier context@(RequestContext _ _ ApiRequest{..} _) = do
-  when (iTopLevelRange /= RangeQuery.allRange) $
-    throwError Error.PutRangeNotAllowedError
-
-  WriteQueryResult{..} <- writeQuery identifier False mempty context
-
-  let response = gucResponse resGucStatus resGucHeaders
-
-  -- Makes sure the querystring pk matches the payload pk
-  -- e.g. PUT /items?id=eq.1 { "id" : 1, .. } is accepted,
-  -- PUT /items?id=eq.14 { "id" : 2, .. } is rejected.
-  -- If this condition is not satisfied then nothing is inserted,
-  -- check the WHERE for INSERT in QueryBuilder.hs to see how it's done
-  when (resQueryTotal /= 1) $ do
-    lift SQL.condemn
-    throwError Error.PutMatchingPkError
-
-  return $
-    if iPreferRepresentation == Full then
-      response HTTP.status200 (contentTypeHeaders context) (LBS.fromStrict resBody)
-    else
-      response HTTP.status204 (contentTypeHeaders context) mempty
-
-handleDelete :: QualifiedIdentifier -> RequestContext -> DbHandler Wai.Response
-handleDelete identifier context@(RequestContext _ _ ApiRequest{..} _) = do
-  WriteQueryResult{..} <- writeQuery identifier False mempty context
-
-  let
-    response = gucResponse resGucStatus resGucHeaders
-    contentRangeHeader =
-      RangeQuery.contentRangeH 1 0 $
-        if shouldCount iPreferCount then Just resQueryTotal else Nothing
-
-  failNotSingular iAcceptContentType resQueryTotal $
-    if iPreferRepresentation == Full then
-      response HTTP.status200
-        (contentTypeHeaders context ++ [contentRangeHeader])
-        (LBS.fromStrict resBody)
-    else
-      response HTTP.status204 [contentRangeHeader] mempty
-
-handleInfo :: Monad m => QualifiedIdentifier -> RequestContext -> Handler m Wai.Response
-handleInfo identifier RequestContext{..} =
-  case find tableMatches $ dbTables ctxDbStructure of
-    Just table ->
-      return $ Wai.responseLBS HTTP.status200 [allOrigins, allowH table] mempty
-    Nothing ->
-      throwError Error.NotFound
-  where
-    allOrigins = ("Access-Control-Allow-Origin", "*")
-    allowH table =
-      ( HTTP.hAllow
-      , BS.intercalate "," $
-          ["OPTIONS,GET,HEAD"]
-          ++ ["POST" | tableInsertable table]
-          ++ ["PUT" | tableInsertable table && tableUpdatable table && hasPK]
-          ++ ["PATCH" | tableUpdatable table]
-          ++ ["DELETE" | tableDeletable table]
-      )
-    tableMatches table =
-      tableName table == qiName identifier
-      && tableSchema table == qiSchema identifier
-    hasPK =
-      not $ null $ tablePKCols ctxDbStructure (qiSchema identifier) (qiName identifier)
-
-handleInvoke :: InvokeMethod -> ProcDescription -> RequestContext -> DbHandler Wai.Response
-handleInvoke invMethod proc context@RequestContext{..} = do
-  let
-    ApiRequest{..} = ctxApiRequest
-
-    identifier =
-      QualifiedIdentifier
-        (pdSchema proc)
-        (fromMaybe (pdName proc) $ Proc.procTableName proc)
-
-  req <- readRequest identifier context
-  bField <- binaryField context req
-
-  let callReq = ReqBuilder.callRequest proc ctxApiRequest req
-
-  (tableTotal, queryTotal, body, gucHeaders, gucStatus) <-
-    lift . SQL.statement mempty $
-      Statements.callProcStatement
-        (Proc.procReturnsScalar proc)
-        (Proc.procReturnsSingle proc)
-        (QueryBuilder.requestToCallProcQuery callReq)
-        (QueryBuilder.readRequestToQuery req)
-        (QueryBuilder.readRequestToCountQuery req)
-        (shouldCount iPreferCount)
-        (iAcceptContentType == CTSingularJSON)
-        (iAcceptContentType == CTTextCSV)
-        (iPreferParameters == Just MultipleObjects)
-        bField
-        (configDbPreparedStatements ctxConfig)
-
-  response <- liftEither $ gucResponse <$> gucStatus <*> gucHeaders
-
-  let
-    (status, contentRange) =
-      RangeQuery.rangeStatusHeader iTopLevelRange queryTotal tableTotal
-
-  failNotSingular iAcceptContentType queryTotal $
-    response status
-      (contentTypeHeaders context ++ [contentRange])
-      (if invMethod == InvHead then mempty else LBS.fromStrict body)
-
-handleOpenApi :: Bool -> Schema -> RequestContext -> DbHandler Wai.Response
-handleOpenApi headersOnly tSchema (RequestContext conf@AppConfig{..} dbStructure apiRequest ctxPgVersion) = do
-  body <-
-    lift $ case configOpenApiMode of
-      OAFollowPriv ->
-        OpenAPI.encode conf dbStructure
-           <$> SQL.statement tSchema (DbStructure.accessibleTables ctxPgVersion configDbPreparedStatements)
-           <*> SQL.statement tSchema (DbStructure.accessibleProcs configDbPreparedStatements)
-           <*> SQL.statement tSchema (DbStructure.schemaDescription configDbPreparedStatements)
-      OAIgnorePriv ->
-        OpenAPI.encode conf dbStructure
-              (filter (\x -> tableSchema x == tSchema) $ DbStructure.dbTables dbStructure)
-              (M.filterWithKey (\(QualifiedIdentifier sch _) _ ->  sch == tSchema) $ DbStructure.dbProcs dbStructure)
-          <$> SQL.statement tSchema (DbStructure.schemaDescription configDbPreparedStatements)
-      OADisabled ->
-        pure mempty
-
-  return $
-    Wai.responseLBS HTTP.status200
-      (ContentType.toHeader CTOpenAPI : maybeToList (profileHeader apiRequest))
-      (if headersOnly then mempty else body)
-
-txMode :: ApiRequest -> SQL.Mode
-txMode ApiRequest{..} =
-  case (iAction, iTarget) of
-    (ActionRead _, _) ->
-      SQL.Read
    (ActionInfo, _) ->
-      SQL.Read
-    (ActionInspect _, _) ->
-      SQL.Read
-    (ActionInvoke InvGet, _) ->
-      SQL.Read
-    (ActionInvoke InvHead, _) ->
-      SQL.Read
-    (ActionInvoke InvPost, TargetProc ProcDescription{pdVolatility=Stable} _) ->
-      SQL.Read
-    (ActionInvoke InvPost, TargetProc ProcDescription{pdVolatility=Immutable} _) ->
-      SQL.Read
+      return $ Response.infoResponse iTarget sCache
+
    _ ->
-      SQL.Write
-
-- | Result from executing a write query on the database
-data WriteQueryResult = WriteQueryResult
-  { resQueryTotal :: Int64
-  , resFields     :: [ByteString]
-  , resBody       :: ByteString
-  , resGucStatus  :: Maybe HTTP.Status
-  , resGucHeaders :: [GucHeader]
-  }
-
-writeQuery :: QualifiedIdentifier -> Bool -> [Text] -> RequestContext -> DbHandler WriteQueryResult
-writeQuery identifier@QualifiedIdentifier{..} isInsert pkCols context@RequestContext{..} = do
-  readReq <- readRequest identifier context
-
-  mutateReq <-
-    liftEither $
-      ReqBuilder.mutateRequest qiSchema qiName ctxApiRequest
-        (tablePKCols ctxDbStructure qiSchema qiName)
-        readReq
-
-  (_, queryTotal, fields, body, gucHeaders, gucStatus) <-
-    lift . SQL.statement mempty $
-      Statements.createWriteStatement
-        (QueryBuilder.readRequestToQuery readReq)
-        (QueryBuilder.mutateRequestToQuery mutateReq)
-        (iAcceptContentType ctxApiRequest == CTSingularJSON)
-        isInsert
-        (iAcceptContentType ctxApiRequest == CTTextCSV)
-        (iPreferRepresentation ctxApiRequest)
-        pkCols
-        (configDbPreparedStatements ctxConfig)
-
-  liftEither $ WriteQueryResult queryTotal fields body <$> gucStatus <*> gucHeaders
-
-- | Response with headers and status overridden from GUCs.
-gucResponse
-  :: Maybe HTTP.Status
-  -> [GucHeader]
-  -> HTTP.Status
-  -> [HTTP.Header]
-  -> LBS.ByteString
-  -> Wai.Response
-gucResponse gucStatus gucHeaders status headers =
-  Wai.responseLBS (fromMaybe status gucStatus) $
-    addHeadersIfNotIncluded headers (map unwrapGucHeader gucHeaders)
-
-- |
-- Fail a response if a single JSON object was requested and not exactly one
-- was found.
-failNotSingular :: ContentType -> Int64 -> Wai.Response -> DbHandler Wai.Response
-failNotSingular contentType queryTotal response =
-  if contentType == CTSingularJSON && queryTotal /= 1 then
-    do
-      lift SQL.condemn
-      throwError $ Error.singularityError queryTotal
-  else
-    return response
-
-shouldCount :: Maybe PreferCount -> Bool
-shouldCount preferCount =
-  preferCount == Just ExactCount || preferCount == Just EstimatedCount
-
-returnsScalar :: ApiRequest.Target -> Bool
-returnsScalar (TargetProc proc _) = Proc.procReturnsScalar proc
-returnsScalar _                   = False
-
-readRequest :: Monad m => QualifiedIdentifier -> RequestContext -> Handler m ReadRequest
-readRequest QualifiedIdentifier{..} (RequestContext AppConfig{..} dbStructure apiRequest _) =
-  liftEither $
-    ReqBuilder.readRequest qiSchema qiName configDbMaxRows
-      (dbRelationships dbStructure)
-      apiRequest
-
-contentTypeHeaders :: RequestContext -> [HTTP.Header]
-contentTypeHeaders RequestContext{..} =
-  ContentType.toHeader (iAcceptContentType ctxApiRequest) : maybeToList (profileHeader ctxApiRequest)
-
-- | If raw(binary) output is requested, check that ContentType is one of the
-- admitted rawContentTypes and that`?select=...` contains only one field other
-- than `*`
-binaryField :: Monad m => RequestContext -> ReadRequest -> Handler m (Maybe FieldName)
-binaryField RequestContext{..} readReq
-  | returnsScalar (iTarget ctxApiRequest) && iAcceptContentType ctxApiRequest `elem` rawContentTypes ctxConfig =
-      return $ Just "pgrst_scalar"
-  | iAcceptContentType ctxApiRequest `elem` rawContentTypes ctxConfig =
-      let
-        fldNames = fstFieldNames readReq
-        fieldName = headMay fldNames
-      in
-      if length fldNames == 1 && fieldName /= Just "*" then
-        return fieldName
-      else
-        throwError $ Error.BinaryFieldError (iAcceptContentType ctxApiRequest)
-  | otherwise =
-      return Nothing
-
-rawContentTypes :: AppConfig -> [ContentType]
-rawContentTypes AppConfig{..} =
-  (ContentType.decodeContentType <$> configRawMediaTypes) `union` [CTOctetStream, CTTextPlain]
-
-profileHeader :: ApiRequest -> Maybe HTTP.Header
-profileHeader ApiRequest{..} =
-  (,) "Content-Profile" <$> (toUtf8 <$> iProfile)
-
-splitKeyValue :: ByteString -> (ByteString, ByteString)
-splitKeyValue kv =
-  (k, BS.tail v)
+      -- This is unreachable as the ApiRequest.hs rejects it before
+      -- TODO Refactor the Action/Target types to remove this line
+      throwError $ Error.ApiRequestError ApiRequestTypes.NotFound
  where
-    (k, v) = BS.break (== '=') kv
+    runQuery query =
+      runDbHandler appState mode authenticated prepared $ do
+        Query.setPgLocals conf authClaims authRole apiReq jsonDbS pgVer
+        query
@@ -2,33 +2,42 @@

 module PostgREST.AppState
  ( AppState
+  , destroy
+  , flushPool
  , getConfig
-  , getDbStructure
-  , getIsWorkerOn
+  , getSchemaCache
+  , getIsListenerOn
  , getJsonDbS
  , getMainThreadId
  , getPgVersion
-  , getPool
-  , getTime
  , getRetryNextIn
+  , getTime
+  , getWorkerSem
  , init
  , initWithPool
  , logWithZTime
+  , logPgrstError
  , putConfig
-  , putDbStructure
-  , putIsWorkerOn
+  , putSchemaCache
+  , putIsListenerOn
  , putJsonDbS
  , putPgVersion
  , putRetryNextIn
-  , releasePool
  , signalListener
+  , usePool
  , waitListener
+  , debounceLogAcquisitionTimeout
  ) where

-import qualified Hasql.Pool as SQL
+import qualified Data.ByteString.Lazy as LBS
+import qualified Data.Text.Encoding   as T
+import qualified Hasql.Pool           as SQL
+import qualified Hasql.Session        as SQL
+import qualified PostgREST.Error      as Error

 import Control.AutoUpdate (defaultUpdateSettings, mkAutoUpdate,
                           updateAction)
+import Control.Debounce
 import Data.IORef         (IORef, atomicWriteIORef, newIORef,
                           readIORef)
 import Data.Time          (ZonedTime, defaultTimeLocale, formatTime,
@@ -37,62 +46,94 @@ import Data.Time.Clock    (UTCTime, getCurrentTime)

 import PostgREST.Config           (AppConfig (..))
 import PostgREST.Config.PgVersion (PgVersion (..), minimumPgVersion)
-import PostgREST.DbStructure      (DbStructure)
+import PostgREST.SchemaCache      (SchemaCache)

 import Protolude


 data AppState = AppState
-  { statePool         :: SQL.Pool -- | Connection pool, either a 'Connection' or a 'ConnectionError'
-  , statePgVersion    :: IORef PgVersion
+  -- | Database connection pool
+  { statePool                     :: SQL.Pool
+  -- | Database server version, will be updated by the connectionWorker
+  , statePgVersion                :: IORef PgVersion
  -- | No schema cache at the start. Will be filled in by the connectionWorker
-  , stateDbStructure  :: IORef (Maybe DbStructure)
-  -- | Cached DbStructure in json
-  , stateJsonDbS      :: IORef ByteString
-  -- | Helper ref to make sure just one connectionWorker can run at a time
-  , stateIsWorkerOn   :: IORef Bool
+  , stateSchemaCache              :: IORef (Maybe SchemaCache)
+  -- | Cached SchemaCache in json
+  , stateJsonDbS                  :: IORef ByteString
+  -- | Binary semaphore to make sure just one connectionWorker can run at a time
+  , stateWorkerSem                :: MVar ()
  -- | Binary semaphore used to sync the listener(NOTIFY reload) with the connectionWorker.
-  , stateListener     :: MVar ()
+  , stateListener                 :: MVar ()
+  -- | State of the LISTEN channel, used for the admin server checks
+  , stateIsListenerOn             :: IORef Bool
  -- | Config that can change at runtime
-  , stateConf         :: IORef AppConfig
+  , stateConf                     :: IORef AppConfig
  -- | Time used for verifying JWT expiration
-  , stateGetTime      :: IO UTCTime
+  , stateGetTime                  :: IO UTCTime
  -- | Time with time zone used for worker logs
-  , stateGetZTime     :: IO ZonedTime
+  , stateGetZTime                 :: IO ZonedTime
  -- | Used for killing the main thread in case a subthread fails
-  , stateMainThreadId :: ThreadId
+  , stateMainThreadId             :: ThreadId
  -- | Keeps track of when the next retry for connecting to database is scheduled
-  , stateRetryNextIn  :: IORef Int
+  , stateRetryNextIn              :: IORef Int
+  -- | Logs a pool error with a debounce
+  , debounceLogAcquisitionTimeout :: IO ()
  }

 init :: AppConfig -> IO AppState
 init conf = do
-  newPool <- initPool conf
-  initWithPool newPool conf
+  pool <- initPool conf
+  initWithPool pool conf

 initWithPool :: SQL.Pool -> AppConfig -> IO AppState
-initWithPool newPool conf =
-  AppState newPool
+initWithPool pool conf = do
+  appState <- AppState pool
    <$> newIORef minimumPgVersion -- assume we're in a supported version when starting, this will be corrected on a later step
    <*> newIORef Nothing
    <*> newIORef mempty
-    <*> newIORef False
    <*> newEmptyMVar
+    <*> newEmptyMVar
+    <*> newIORef False
    <*> newIORef conf
    <*> mkAutoUpdate defaultUpdateSettings { updateAction = getCurrentTime }
    <*> mkAutoUpdate defaultUpdateSettings { updateAction = getZonedTime }
    <*> myThreadId
    <*> newIORef 0
+    <*> pure (pure ())
+
+  deb <-
+    let oneSecond = 1000000 in
+    mkDebounce defaultDebounceSettings
+       { debounceAction = logPgrstError appState SQL.AcquisitionTimeoutUsageError
+       , debounceFreq = 5*oneSecond
+       , debounceEdge = leadingEdge -- logs at the start and the end
+       }
+
+  return appState { debounceLogAcquisitionTimeout = deb }
+
+destroy :: AppState -> IO ()
+destroy = destroyPool

 initPool :: AppConfig -> IO SQL.Pool
 initPool AppConfig{..} =
-  SQL.acquire (configDbPoolSize, configDbPoolTimeout, toUtf8 configDbUri)
+  SQL.acquire
+    configDbPoolSize
+    (fromIntegral configDbPoolAcquisitionTimeout)
+    (fromIntegral configDbPoolMaxLifetime)
+    (toUtf8 configDbUri)

-getPool :: AppState -> SQL.Pool
-getPool = statePool
+-- | Run an action with a database connection.
+usePool :: AppState -> SQL.Session a -> IO (Either SQL.UsageError a)
+usePool AppState{..} = SQL.use statePool

-releasePool :: AppState -> IO ()
-releasePool AppState{..} = SQL.release statePool >> throwTo stateMainThreadId UserInterrupt
+-- | Flush the connection pool so that any future use of the pool will
+-- use connections freshly established after this call.
+flushPool :: AppState -> IO ()
+flushPool AppState{..} = SQL.release statePool
+
+-- | Destroy the pool on shutdown.
+destroyPool :: AppState -> IO ()
+destroyPool AppState{..} = SQL.release statePool

 getPgVersion :: AppState -> IO PgVersion
 getPgVersion = readIORef . statePgVersion
@@ -100,12 +141,11 @@ getPgVersion = readIORef . statePgVersion
 putPgVersion :: AppState -> PgVersion -> IO ()
 putPgVersion = atomicWriteIORef . statePgVersion

-getDbStructure :: AppState -> IO (Maybe DbStructure)
-getDbStructure = readIORef . stateDbStructure
+getSchemaCache :: AppState -> IO (Maybe SchemaCache)
+getSchemaCache = readIORef . stateSchemaCache

-putDbStructure :: AppState -> DbStructure -> IO ()
-putDbStructure appState structure =
-  atomicWriteIORef (stateDbStructure appState) $ Just structure
+putSchemaCache :: AppState -> Maybe SchemaCache -> IO ()
+putSchemaCache appState = atomicWriteIORef (stateSchemaCache appState)

 getJsonDbS :: AppState -> IO ByteString
 getJsonDbS = readIORef . stateJsonDbS
@@ -113,11 +153,8 @@ getJsonDbS = readIORef . stateJsonDbS
 putJsonDbS :: AppState -> ByteString -> IO ()
 putJsonDbS appState = atomicWriteIORef (stateJsonDbS appState)

-getIsWorkerOn :: AppState -> IO Bool
-getIsWorkerOn = readIORef . stateIsWorkerOn
-
-putIsWorkerOn :: AppState -> Bool -> IO ()
-putIsWorkerOn = atomicWriteIORef . stateIsWorkerOn
+getWorkerSem :: AppState -> MVar ()
+getWorkerSem = stateWorkerSem

 getRetryNextIn :: AppState -> IO Int
 getRetryNextIn = readIORef . stateRetryNextIn
@@ -140,6 +177,9 @@ logWithZTime appState txt = do
  zTime <- stateGetZTime appState
  hPutStrLn stderr $ toS (formatTime defaultTimeLocale "%d/%b/%Y:%T %z: " zTime) <> txt

+logPgrstError :: AppState -> SQL.UsageError -> IO ()
+logPgrstError appState e = logWithZTime appState . T.decodeUtf8 . LBS.toStrict $ Error.errorPayload $ Error.PgError False e
+
 getMainThreadId :: AppState -> ThreadId
 getMainThreadId = stateMainThreadId

@@ -153,3 +193,9 @@ waitListener = takeMVar . stateListener
 -- the connectionWorker is the only mvar producer.
 signalListener :: AppState -> IO ()
 signalListener appState = void $ tryPutMVar (stateListener appState) ()
+
+getIsListenerOn :: AppState -> IO Bool
+getIsListenerOn = readIORef . stateIsListenerOn
+
+putIsListenerOn :: AppState -> Bool -> IO ()
+putIsListenerOn = atomicWriteIORef . stateIsListenerOn
@@ -12,40 +12,55 @@ very simple authentication system inside the PostgreSQL database.
 -}
 {-# LANGUAGE RecordWildCards #-}
 module PostgREST.Auth
-  ( containsRole
-  , jwtClaims
-  , JWTClaims
+  ( AuthResult (..)
+  , getResult
+  , getRole
+  , middleware
  ) where

-import qualified Crypto.JWT          as JWT
-import qualified Data.Aeson          as JSON
-import qualified Data.HashMap.Strict as M
-import qualified Data.Vector         as V
+import qualified Crypto.JWT                      as JWT
+import qualified Data.Aeson                      as JSON
+import qualified Data.Aeson.Key                  as K
+import qualified Data.Aeson.KeyMap               as KM
+import qualified Data.Aeson.Types                as JSON
+import qualified Data.ByteString.Lazy.Char8      as LBS
+import qualified Data.Text.Encoding              as T
+import qualified Data.Vault.Lazy                 as Vault
+import qualified Data.Vector                     as V
+import qualified Network.HTTP.Types.Header       as HTTP
+import qualified Network.Wai                     as Wai
+import qualified Network.Wai.Middleware.HttpAuth as Wai

 import Control.Lens            (set)
 import Control.Monad.Except    (liftEither)
 import Data.Either.Combinators (mapLeft)
+import Data.List               (lookup)
 import Data.Time.Clock         (UTCTime)
+import System.IO.Unsafe        (unsafePerformIO)

-import PostgREST.Config (AppConfig (..), JSPath, JSPathExp (..))
-import PostgREST.Error  (Error (..))
+import PostgREST.AppState (AppState, getConfig, getTime)
+import PostgREST.Config   (AppConfig (..), JSPath, JSPathExp (..))
+import PostgREST.Error    (Error (..))

 import Protolude


-type JWTClaims = M.HashMap Text JSON.Value
+data AuthResult = AuthResult
+  { authClaims :: KM.KeyMap JSON.Value
+  , authRole   :: Text
+  }

 -- | Receives the JWT secret and audience (from config) and a JWT and returns a
-- map of JWT claims.
-jwtClaims :: Monad m =>
-  AppConfig -> LByteString -> UTCTime -> ExceptT Error m JWTClaims
-jwtClaims _ "" _ = return M.empty
-jwtClaims AppConfig{..} payload time = do
+-- JSON object of JWT claims.
+parseToken :: Monad m =>
+  AppConfig -> LByteString -> UTCTime -> ExceptT Error m JSON.Value
+parseToken _ "" _ = return JSON.emptyObject
+parseToken AppConfig{..} token time = do
  secret <- liftEither . maybeToRight JwtTokenMissing $ configJWKS
  eitherClaims <-
    lift . runExceptT $
-      JWT.verifyClaimsAt validation secret time =<< JWT.decodeCompact payload
-  liftEither . mapLeft jwtClaimsError $ claimsMap configJwtRoleClaimKey <$> eitherClaims
+      JWT.verifyClaimsAt validation secret time =<< JWT.decodeCompact token
+  liftEither . mapLeft jwtClaimsError $ JSON.toJSON <$> eitherClaims
  where
    validation =
      JWT.defaultJWTValidationSettings audienceCheck & set JWT.allowedSkew 1
@@ -57,26 +72,50 @@ jwtClaims AppConfig{..} payload time = do
    jwtClaimsError JWT.JWTExpired = JwtTokenInvalid "JWT expired"
    jwtClaimsError e              = JwtTokenInvalid $ show e

-- | Turn JWT ClaimSet into something easier to work with.
--
-- Also, here the jspath is applied to put the "role" in the map.
-claimsMap :: JSPath -> JWT.ClaimsSet -> JWTClaims
-claimsMap jspath claims =
-  case JSON.toJSON claims of
-    val@(JSON.Object o) ->
-      M.delete "role" o `M.union` role val
-    _ ->
-      M.empty
+parseClaims :: Monad m =>
+  AppConfig -> JSON.Value -> ExceptT Error m AuthResult
+parseClaims AppConfig{..} jclaims@(JSON.Object mclaims) = do
+  -- role defaults to anon if not specified in jwt
+  role <- liftEither . maybeToRight JwtTokenRequired $
+    unquoted <$> walkJSPath (Just jclaims) configJwtRoleClaimKey <|> configDbAnonRole
+  return AuthResult
+           { authClaims = mclaims & KM.insert "role" (JSON.toJSON role)
+           , authRole = role
+           }
  where
-    role value =
-      maybe M.empty (M.singleton "role") $ walkJSPath (Just value) jspath
-
    walkJSPath :: Maybe JSON.Value -> JSPath -> Maybe JSON.Value
    walkJSPath x                      []                = x
-    walkJSPath (Just (JSON.Object o)) (JSPKey key:rest) = walkJSPath (M.lookup key o) rest
+    walkJSPath (Just (JSON.Object o)) (JSPKey key:rest) = walkJSPath (KM.lookup (K.fromText key) o) rest
    walkJSPath (Just (JSON.Array ar)) (JSPIdx idx:rest) = walkJSPath (ar V.!? idx) rest
    walkJSPath _                      _                 = Nothing

-- | Whether a response from jwtClaims contains a role claim
-containsRole :: JWTClaims -> Bool
-containsRole = M.member "role"
+    unquoted :: JSON.Value -> Text
+    unquoted (JSON.String t) = t
+    unquoted v = T.decodeUtf8 . LBS.toStrict $ JSON.encode v
+-- impossible case - just added to please -Wincomplete-patterns
+parseClaims _ _ = return AuthResult { authClaims = KM.empty, authRole = mempty }
+
+-- | Validate authorization header.
+--   Parse and store JWT claims for future use in the request.
+middleware :: AppState -> Wai.Middleware
+middleware appState app req respond = do
+  conf <- getConfig appState
+  time <- getTime appState
+
+  let token = fromMaybe "" $ Wai.extractBearerAuth =<< lookup HTTP.hAuthorization (Wai.requestHeaders req)
+  authResult <- runExceptT $
+    parseToken conf (LBS.fromStrict token) time >>=
+    parseClaims conf
+
+  let req' = req { Wai.vault = Wai.vault req & Vault.insert authResultKey authResult }
+  app req' respond
+
+authResultKey :: Vault.Key (Either Error AuthResult)
+authResultKey = unsafePerformIO Vault.newKey
+{-# NOINLINE authResultKey #-}
+
+getResult :: Wai.Request -> Maybe (Either Error AuthResult)
+getResult = Vault.lookup authResultKey . Wai.vault
+
+getRole :: Wai.Request -> Maybe Text
+getRole req = authRole <$> (rightToMaybe =<< getResult req)
@@ -11,7 +11,6 @@ module PostgREST.CLI
 import qualified Data.Aeson                 as JSON
 import qualified Data.ByteString.Char8      as BS
 import qualified Data.ByteString.Lazy       as LBS
-import qualified Hasql.Pool                 as SQL
 import qualified Hasql.Transaction.Sessions as SQL
 import qualified Options.Applicative        as O

@@ -20,7 +19,7 @@ import Text.Heredoc (str)

 import PostgREST.AppState    (AppState)
 import PostgREST.Config      (AppConfig (..))
-import PostgREST.DbStructure (queryDbStructure)
+import PostgREST.SchemaCache (querySchemaCache)
 import PostgREST.Version     (prettyVersion)
 import PostgREST.Workers     (reReadConfig)

@@ -35,40 +34,37 @@ main :: App.SignalHandlerInstaller -> Maybe App.SocketRunner -> CLI -> IO ()
 main installSignalHandlers runAppWithSocket CLI{cliCommand, cliPath} = do
  conf@AppConfig{..} <-
    either panic identity <$> Config.readAppConfig mempty cliPath Nothing
-  appState <- AppState.init conf

-  -- Override the config with config options from the db
-  -- TODO: the same operation is repeated on connectionWorker, ideally this
-  -- would be done only once, but dump CmdDumpConfig needs it for tests.
-  when configDbConfig $ reReadConfig True appState
+  -- Per https://github.com/PostgREST/postgrest/issues/268, we want to
+  -- explicitly close the connections to PostgreSQL on shutdown.
+  -- 'AppState.destroy' takes care of that.
+  bracket
+    (AppState.init conf)
+    AppState.destroy
+    (\appState -> case cliCommand of
+      CmdDumpConfig -> do
+        when configDbConfig $ reReadConfig True appState
+        putStr . Config.toText =<< AppState.getConfig appState
+      CmdDumpSchema -> putStrLn =<< dumpSchema appState
+      CmdRun -> App.run installSignalHandlers runAppWithSocket appState)

-  exec cliCommand appState
-  where
-    exec :: Command -> AppState -> IO ()
-    exec CmdDumpConfig appState = putStr . Config.toText =<< AppState.getConfig appState
-    exec CmdDumpSchema appState = putStrLn =<< dumpSchema appState
-    exec CmdRun appState = App.run installSignalHandlers runAppWithSocket appState
-
-- | Dump DbStructure schema to JSON
+-- | Dump SchemaCache schema to JSON
 dumpSchema :: AppState -> IO LBS.ByteString
 dumpSchema appState = do
  AppConfig{..} <- AppState.getConfig appState
-  actualPgVersion <- AppState.getPgVersion appState
  result <-
    let transaction = if configDbPreparedStatements then SQL.transaction else SQL.unpreparedTransaction in
-    SQL.use (AppState.getPool appState) $
+    AppState.usePool appState $
      transaction SQL.ReadCommitted SQL.Read $
-        queryDbStructure
+        querySchemaCache
          (toList configDbSchemas)
          configDbExtraSearchPath
-          actualPgVersion
          configDbPreparedStatements
-  SQL.release $ AppState.getPool appState
  case result of
    Left e -> do
      hPutStrLn stderr $ "An error ocurred when loading the schema cache:\n" <> show e
      exitFailure
-    Right dbStructure -> return $ JSON.encode dbStructure
+    Right sCache -> return $ JSON.encode sCache

 -- | Command line interface options
 data CLI = CLI
@@ -82,12 +78,12 @@ data Command
  | CmdDumpSchema

 -- | Read command line interface options. Also prints help.
-readCLIShowHelp :: Bool -> IO CLI
-readCLIShowHelp hasEnvironment =
+readCLIShowHelp :: IO CLI
+readCLIShowHelp =
  O.customExecParser prefs opts
  where
    prefs = O.prefs $ O.showHelpOnError <> O.showHelpOnEmpty
-    opts = O.info parser $ O.fullDesc <> progDesc <> footer
+    opts = O.info parser $ O.fullDesc <> progDesc
    parser = O.helper <*> exampleParser <*> cliParser

    progDesc =
@@ -96,11 +92,6 @@ readCLIShowHelp hasEnvironment =
        <> BS.unpack prettyVersion
        <> " / create a REST API to an existing Postgres database"

-    footer =
-      O.footer $
-        "To run PostgREST, please pass the FILENAME argument"
-        <> " or set PGRST_ environment variables."
-
    exampleParser =
      O.infoOption exampleConfigFile $
        O.long "example"
@@ -111,12 +102,12 @@ readCLIShowHelp hasEnvironment =
    cliParser =
      CLI
        <$> (dumpConfigFlag <|> dumpSchemaFlag)
-        <*> optionalIf hasEnvironment configFileOption
+        <*> O.optional configFileOption

    configFileOption =
      O.strArgument $
        O.metavar "FILENAME"
-        <> O.help "Path to configuration file (optional with PGRST_ environment variables)"
+        <> O.help "Path to configuration file"

    dumpConfigFlag =
      O.flag CmdRun CmdDumpConfig $
@@ -128,36 +119,13 @@ readCLIShowHelp hasEnvironment =
        O.long "dump-schema"
        <> O.help "Dump loaded schema as JSON and exit (for debugging, output structure is unstable)"

-    optionalIf :: Alternative f => Bool -> f a -> f (Maybe a)
-    optionalIf True  = O.optional
-    optionalIf False = fmap Just
-
 exampleConfigFile :: [Char]
 exampleConfigFile =
-  [str|### REQUIRED:
-      |db-uri = "postgres://user:pass@localhost:5432/dbname"
-      |db-schema = "public"
-      |db-anon-role = "postgres"
+  [str|## Admin server used for checks. It's disabled by default unless a port is specified.
+      |# admin-server-port = 3001
      |
-      |### OPTIONAL:
-      |## number of open connections in the pool
-      |db-pool = 10
-      |
-      |## Time to live, in seconds, for an idle database pool connection.
-      |db-pool-timeout = 10
-      |
-      |## extra schemas to add to the search_path of every request
-      |db-extra-search-path = "public"
-      |
-      |## limit rows in response
-      |# db-max-rows = 1000
-      |
-      |## stored proc to exec immediately after auth
-      |# db-pre-request = "stored_proc_name"
-      |
-      |## stored proc that overrides the root "/" spec
-      |## it must be inside the db-schema
-      |# db-root-spec = "stored_proc_name"
+      |## The database role to use when no client authentication is provided
+      |# db-anon-role = "anon"
      |
      |## Notification channel for reloading the schema cache
      |db-channel = "pgrst"
@@ -168,56 +136,85 @@ exampleConfigFile =
      |## Enable in-database configuration
      |db-config = true
      |
+      |## Extra schemas to add to the search_path of every request
+      |db-extra-search-path = "public"
+      |
+      |## Limit rows in response
+      |# db-max-rows = 1000
+      |
+      |## Allow getting the EXPLAIN plan through the `Accept: application/vnd.pgrst.plan` header
+      |# db-plan-enabled = false
+      |
+      |## Number of open connections in the pool
+      |db-pool = 10
+      |
+      |## Time in seconds to wait to acquire a slot from the connection pool
+      |# db-pool-acquisition-timeout = 10
+      |
+      |## Time in seconds after which to recycle pool connections
+      |# db-pool-max-lifetime = 1800
+      |
+      |## Stored proc to exec immediately after auth
+      |# db-pre-request = "stored_proc_name"
+      |
+      |## Enable or disable prepared statements. disabling is only necessary when behind a connection pooler.
+      |## When disabled, statements will be parametrized but won't be prepared.
+      |db-prepared-statements = true
+      |
+      |## The name of which database schema to expose to REST clients
+      |db-schemas = "public"
+      |
+      |## How to terminate database transactions
+      |## Possible values are:
+      |## commit (default)
+      |##   Transaction is always committed, this can not be overriden
+      |## commit-allow-override
+      |##   Transaction is committed, but can be overriden with Prefer tx=rollback header
+      |## rollback
+      |##   Transaction is always rolled back, this can not be overriden
+      |## rollback-allow-override
+      |##   Transaction is rolled back, but can be overriden with Prefer tx=commit header
+      |db-tx-end = "commit"
+      |
+      |## The standard connection URI format, documented at
+      |## https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNSTRING
+      |db-uri = "postgresql://"
+      |
      |## Determine if GUC request settings for headers, cookies and jwt claims use the legacy names (string with dashes, invalid starting from PostgreSQL v14) with text values instead of the new names (string without dashes, valid on all PostgreSQL versions) with json values.
      |## For PostgreSQL v14 and up, this setting will be ignored.
      |db-use-legacy-gucs = true
      |
-      |## how to terminate database transactions
-      |## possible values are:
-      |## commit (default)
-      |##   transaction is always committed, this can not be overriden
-      |## commit-allow-override
-      |##   transaction is committed, but can be overriden with Prefer tx=rollback header
-      |## rollback
-      |##   transaction is always rolled back, this can not be overriden
-      |## rollback-allow-override
-      |##   transaction is rolled back, but can be overriden with Prefer tx=commit header
-      |db-tx-end = "commit"
+      |# jwt-aud = "your_audience_claim"
      |
-      |## enable or disable prepared statements. disabling is only necessary when behind a connection pooler.
-      |## when disabled, statements will be parametrized but won't be prepared.
-      |db-prepared-statements = true
+      |## Jspath to the role claim key
+      |jwt-role-claim-key = ".role"
+      |
+      |## Choose a secret, JSON Web Key (or set) to enable JWT auth
+      |## (use "@filename" to load from separate file)
+      |# jwt-secret = "secret_with_at_least_32_characters"
+      |jwt-secret-is-base64 = false
+      |
+      |## Logging level, the admitted values are: crit, error, warn and info.
+      |log-level = "error"
+      |
+      |## Determine if the OpenAPI output should follow or ignore role privileges or be disabled entirely.
+      |## Admitted values: follow-privileges, ignore-privileges, disabled
+      |openapi-mode = "follow-privileges"
+      |
+      |## Base url for the OpenAPI output
+      |openapi-server-proxy-uri = ""
+      |
+      |## Content types to produce raw output
+      |# raw-media-types="image/png, image/jpg"
      |
      |server-host = "!4"
      |server-port = 3000
      |
-      |## unix socket location
+      |## Unix socket location
      |## if specified it takes precedence over server-port
      |# server-unix-socket = "/tmp/pgrst.sock"
      |
-      |## unix socket file mode
-      |## when none is provided, 660 is applied by default
+      |## Unix socket file mode
+      |## When none is provided, 660 is applied by default
      |# server-unix-socket-mode = "660"
-      |
-      |## determine if the OpenAPI output should follow or ignore role privileges or be disabled entirely
-      |## admitted values: follow-privileges, ignore-privileges, disabled
-      |openapi-mode = "follow-privileges"
-      |
-      |## base url for the OpenAPI output
-      |openapi-server-proxy-uri = ""
-      |
-      |## choose a secret, JSON Web Key (or set) to enable JWT auth
-      |## (use "@filename" to load from separate file)
-      |# jwt-secret = "secret_with_at_least_32_characters"
-      |# jwt-aud = "your_audience_claim"
-      |jwt-secret-is-base64 = false
-      |
-      |## jspath to the role claim key
-      |jwt-role-claim-key = ".role"
-      |
-      |## content types to produce raw output
-      |# raw-media-types="image/png, image/jpg"
-      |
-      |## logging level, the admitted values are: crit, error, warn and info.
-      |log-level = "error"
      |]
@@ -46,7 +46,6 @@ import Data.List               (lookup)
 import Data.List.NonEmpty      (fromList, toList)
 import Data.Maybe              (fromJust)
 import Data.Scientific         (floatingOrInteger)
-import Data.Time.Clock         (NominalDiffTime)
 import Numeric                 (readOct, showOct)
 import System.Environment      (getEnvironment)
 import System.Posix.Types      (FileMode)
@@ -55,44 +54,49 @@ import PostgREST.Config.JSPath           (JSPath, JSPathExp (..),
                                          dumpJSPath, pRoleClaimKey)
 import PostgREST.Config.Proxy            (Proxy (..),
                                          isMalformedProxyUri, toURI)
-import PostgREST.DbStructure.Identifiers (QualifiedIdentifier, dumpQi,
+import PostgREST.MediaType               (MediaType (..), toMime)
+import PostgREST.SchemaCache.Identifiers (QualifiedIdentifier, dumpQi,
                                          toQi)

 import Protolude hiding (Proxy, toList)


 data AppConfig = AppConfig
-  { configAppSettings           :: [(Text, Text)]
-  , configDbAnonRole            :: Text
-  , configDbChannel             :: Text
-  , configDbChannelEnabled      :: Bool
-  , configDbExtraSearchPath     :: [Text]
-  , configDbMaxRows             :: Maybe Integer
-  , configDbPoolSize            :: Int
-  , configDbPoolTimeout         :: NominalDiffTime
-  , configDbPreRequest          :: Maybe QualifiedIdentifier
-  , configDbPreparedStatements  :: Bool
-  , configDbRootSpec            :: Maybe QualifiedIdentifier
-  , configDbSchemas             :: NonEmpty Text
-  , configDbConfig              :: Bool
-  , configDbTxAllowOverride     :: Bool
-  , configDbTxRollbackAll       :: Bool
-  , configDbUri                 :: Text
-  , configDbUseLegacyGucs       :: Bool
-  , configFilePath              :: Maybe FilePath
-  , configJWKS                  :: Maybe JWKSet
-  , configJwtAudience           :: Maybe StringOrURI
-  , configJwtRoleClaimKey       :: JSPath
-  , configJwtSecret             :: Maybe BS.ByteString
-  , configJwtSecretIsBase64     :: Bool
-  , configLogLevel              :: LogLevel
-  , configOpenApiMode           :: OpenAPIMode
-  , configOpenApiServerProxyUri :: Maybe Text
-  , configRawMediaTypes         :: [BS.ByteString]
-  , configServerHost            :: Text
-  , configServerPort            :: Int
-  , configServerUnixSocket      :: Maybe FilePath
-  , configServerUnixSocketMode  :: FileMode
+  { configAppSettings              :: [(Text, Text)]
+  , configDbAnonRole               :: Maybe Text
+  , configDbChannel                :: Text
+  , configDbChannelEnabled         :: Bool
+  , configDbExtraSearchPath        :: [Text]
+  , configDbMaxRows                :: Maybe Integer
+  , configDbPlanEnabled            :: Bool
+  , configDbPoolSize               :: Int
+  , configDbPoolAcquisitionTimeout :: Int
+  , configDbPoolMaxLifetime        :: Int
+  , configDbPreRequest             :: Maybe QualifiedIdentifier
+  , configDbPreparedStatements     :: Bool
+  , configDbRootSpec               :: Maybe QualifiedIdentifier
+  , configDbSchemas                :: NonEmpty Text
+  , configDbConfig                 :: Bool
+  , configDbTxAllowOverride        :: Bool
+  , configDbTxRollbackAll          :: Bool
+  , configDbUri                    :: Text
+  , configDbUseLegacyGucs          :: Bool
+  , configFilePath                 :: Maybe FilePath
+  , configJWKS                     :: Maybe JWKSet
+  , configJwtAudience              :: Maybe StringOrURI
+  , configJwtRoleClaimKey          :: JSPath
+  , configJwtSecret                :: Maybe BS.ByteString
+  , configJwtSecretIsBase64        :: Bool
+  , configLogLevel                 :: LogLevel
+  , configOpenApiMode              :: OpenAPIMode
+  , configOpenApiSecurityActive    :: Bool
+  , configOpenApiServerProxyUri    :: Maybe Text
+  , configRawMediaTypes            :: [MediaType]
+  , configServerHost               :: Text
+  , configServerPort               :: Int
+  , configServerUnixSocket         :: Maybe FilePath
+  , configServerUnixSocketMode     :: FileMode
+  , configAdminServerPort          :: Maybe Int
  }

 data LogLevel = LogCrit | LogError | LogWarn | LogInfo
@@ -120,18 +124,20 @@ toText conf =
  where
    -- apply conf to all pgrst settings
    pgrstSettings = (\(k, v) -> (k, v conf)) <$>
-      [("db-anon-role",              q . configDbAnonRole)
+      [("db-anon-role",              q . fromMaybe "" . configDbAnonRole)
      ,("db-channel",                q . configDbChannel)
      ,("db-channel-enabled",            T.toLower . show . configDbChannelEnabled)
      ,("db-extra-search-path",      q . T.intercalate "," . configDbExtraSearchPath)
      ,("db-max-rows",                   maybe "\"\"" show . configDbMaxRows)
+      ,("db-plan-enabled",               T.toLower . show . configDbPlanEnabled)
      ,("db-pool",                       show . configDbPoolSize)
-      ,("db-pool-timeout",               show . floor . configDbPoolTimeout)
+      ,("db-pool-acquisition-timeout",   show . configDbPoolAcquisitionTimeout)
+      ,("db-pool-max-lifetime",          show . configDbPoolMaxLifetime)
      ,("db-pre-request",            q . maybe mempty dumpQi . configDbPreRequest)
      ,("db-prepared-statements",        T.toLower . show . configDbPreparedStatements)
      ,("db-root-spec",              q . maybe mempty dumpQi . configDbRootSpec)
      ,("db-schemas",                q . T.intercalate "," . toList . configDbSchemas)
-      ,("db-config",                 q . T.toLower . show . configDbConfig)
+      ,("db-config",                     T.toLower . show . configDbConfig)
      ,("db-tx-end",                 q . showTxEnd)
      ,("db-uri",                    q . configDbUri)
      ,("db-use-legacy-gucs",            T.toLower . show . configDbUseLegacyGucs)
@@ -141,12 +147,14 @@ toText conf =
      ,("jwt-secret-is-base64",          T.toLower . show . configJwtSecretIsBase64)
      ,("log-level",                 q . dumpLogLevel . configLogLevel)
      ,("openapi-mode",              q . dumpOpenApiMode . configOpenApiMode)
+      ,("openapi-security-active",       T.toLower . show . configOpenApiSecurityActive)
      ,("openapi-server-proxy-uri",  q . fromMaybe mempty . configOpenApiServerProxyUri)
-      ,("raw-media-types",           q . T.decodeUtf8 . BS.intercalate "," . configRawMediaTypes)
+      ,("raw-media-types",           q . T.decodeUtf8 . BS.intercalate "," . fmap toMime . configRawMediaTypes)
      ,("server-host",               q . configServerHost)
      ,("server-port",                   show . configServerPort)
      ,("server-unix-socket",        q . maybe mempty T.pack . configServerUnixSocket)
      ,("server-unix-socket-mode",   q . T.pack . showSocketMode)
+      ,("admin-server-port",             maybe "\"\"" show . configAdminServerPort)
      ]

    -- quote all app.settings
@@ -173,10 +181,10 @@ class JustIfMaybe a b where
  justIfMaybe :: a -> b

 instance JustIfMaybe a a where
-  justIfMaybe a = a
+  justIfMaybe = identity

 instance JustIfMaybe a (Maybe a) where
-  justIfMaybe a = Just a
+  justIfMaybe = Just

 -- | Reads and parses the config and overrides its parameters from env vars,
 -- files or db settings.
@@ -205,26 +213,27 @@ parser :: Maybe FilePath -> Environment -> [(Text, Text)] -> C.Parser C.Config A
 parser optPath env dbSettings =
  AppConfig
    <$> parseAppSettings "app.settings"
-    <*> reqString "db-anon-role"
+    <*> optString "db-anon-role"
    <*> (fromMaybe "pgrst" <$> optString "db-channel")
    <*> (fromMaybe True <$> optBool "db-channel-enabled")
    <*> (maybe ["public"] splitOnCommas <$> optValue "db-extra-search-path")
    <*> optWithAlias (optInt "db-max-rows")
                     (optInt "max-rows")
+    <*> (fromMaybe False <$> optBool "db-plan-enabled")
    <*> (fromMaybe 10 <$> optInt "db-pool")
-    <*> (fromIntegral . fromMaybe 10 <$> optInt "db-pool-timeout")
+    <*> (fromMaybe 10 <$> optInt "db-pool-acquisition-timeout")
+    <*> (fromMaybe 1800 <$> optInt "db-pool-max-lifetime")
    <*> (fmap toQi <$> optWithAlias (optString "db-pre-request")
                                    (optString "pre-request"))
    <*> (fromMaybe True <$> optBool "db-prepared-statements")
    <*> (fmap toQi <$> optWithAlias (optString "db-root-spec")
                                    (optString "root-spec"))
-    <*> (fromList . splitOnCommas <$> reqWithAlias (optValue "db-schemas")
-                                                   (optValue "db-schema")
-                                                   "missing key: either db-schemas or db-schema must be set")
+    <*> (fromList . maybe ["public"] splitOnCommas <$> optWithAlias (optValue "db-schemas")
+                                                                    (optValue "db-schema"))
    <*> (fromMaybe True <$> optBool "db-config")
    <*> parseTxEnd "db-tx-end" snd
    <*> parseTxEnd "db-tx-end" fst
-    <*> reqString "db-uri"
+    <*> (fromMaybe "postgresql://" <$> optString "db-uri")
    <*> (fromMaybe True <$> optBool "db-use-legacy-gucs")
    <*> pure optPath
    <*> pure Nothing
@@ -236,12 +245,14 @@ parser optPath env dbSettings =
          (optBool "secret-is-base64"))
    <*> parseLogLevel "log-level"
    <*> parseOpenAPIMode "openapi-mode"
+    <*> (fromMaybe False <$> optBool "openapi-security-active")
    <*> parseOpenAPIServerProxyURI "openapi-server-proxy-uri"
-    <*> (maybe [] (fmap encodeUtf8 . splitOnCommas) <$> optValue "raw-media-types")
+    <*> (maybe [] (fmap (MTOther . encodeUtf8) . splitOnCommas) <$> optValue "raw-media-types")
    <*> (fromMaybe "!4" <$> optString "server-host")
    <*> (fromMaybe 3000 <$> optInt "server-port")
    <*> (fmap T.unpack <$> optString "server-unix-socket")
    <*> parseSocketFileMode "server-unix-socket-mode"
+    <*> optInt "admin-server-port"
  where
    parseAppSettings :: C.Key -> C.Parser C.Config [(Text, Text)]
    parseAppSettings key = addFromEnv . fmap (fmap coerceText) <$> C.subassocs key C.value
@@ -314,24 +325,12 @@ parser optPath env dbSettings =
        Nothing  -> pure [JSPKey "role"]
        Just rck -> either (fail . show) pure $ pRoleClaimKey rck

-    reqWithAlias :: C.Parser C.Config (Maybe a) -> C.Parser C.Config (Maybe a) -> [Char] -> C.Parser C.Config a
-    reqWithAlias orig alias err =
-      orig >>= \case
-        Just v  -> pure v
-        Nothing ->
-          alias >>= \case
-            Just v  -> pure v
-            Nothing -> fail err
-
    optWithAlias :: C.Parser C.Config (Maybe a) -> C.Parser C.Config (Maybe a) -> C.Parser C.Config (Maybe a)
    optWithAlias orig alias =
      orig >>= \case
        Just v  -> pure $ Just v
        Nothing -> alias

-    reqString :: C.Key -> C.Parser C.Config Text
-    reqString k = overrideFromDbOrEnvironment C.required k coerceText
-
    optString :: C.Key -> C.Parser C.Config (Maybe Text)
    optString k = mfilter (/= "") <$> overrideFromDbOrEnvironment C.optional k coerceText

@@ -358,8 +357,9 @@ parser optPath env dbSettings =
        reloadableDbSetting =
          let dbSettingName = T.pack $ dashToUnderscore <$> toS key in
          if dbSettingName `notElem` [
-            "server_host", "server_port", "server_unix_socket", "server_unix_socket_mode", "log_level",
-            "db_anon_role", "db_uri", "db_channel_enabled", "db_channel", "db_pool", "db_pool_timeout", "db_config"]
+            "server_host", "server_port", "server_unix_socket", "server_unix_socket_mode", "admin_server_port", "log_level",
+            "db_uri", "db_channel_enabled", "db_channel", "db_pool", "db_pool_acquisition_timeout",
+            "db_pool_max_lifetime", "db_config"]
          then lookup dbSettingName dbSettings
          else Nothing

@@ -369,17 +369,17 @@ parser optPath env dbSettings =

    coerceInt :: (Read i, Integral i) => C.Value -> Maybe i
    coerceInt (C.Number x) = rightToMaybe $ floatingOrInteger x
-    coerceInt (C.String x) = readMaybe $ toS x
+    coerceInt (C.String x) = readMaybe x
    coerceInt _            = Nothing

    coerceBool :: C.Value -> Maybe Bool
    coerceBool (C.Bool b)   = Just b
    coerceBool (C.String s) =
      -- parse all kinds of text: True, true, TRUE, "true", ...
-      case readMaybe . toS $ T.toTitle $ T.filter isAlpha $ toS s of
+      case readMaybe $ T.toTitle $ T.filter isAlpha $ toS s of
        Just b  -> Just b
        -- numeric instead?
-        Nothing -> (> 0) <$> (readMaybe $ toS s :: Maybe Integer)
+        Nothing -> (> 0) <$> (readMaybe s :: Maybe Integer)
    coerceBool _            = Nothing

    splitOnCommas :: C.Value -> [Text]
@@ -1,7 +1,8 @@
 {-# LANGUAGE QuasiQuotes #-}

 module PostgREST.Config.Database
-  ( queryDbSettings
+  ( pgVersionStatement
+  , queryDbSettings
  , queryPgVersion
  ) where

@@ -9,7 +10,6 @@ import PostgREST.Config.PgVersion (PgVersion (..))

 import qualified Hasql.Decoders             as HD
 import qualified Hasql.Encoders             as HE
-import qualified Hasql.Pool                 as SQL
 import           Hasql.Session              (Session, statement)
 import qualified Hasql.Statement            as SQL
 import qualified Hasql.Transaction          as SQL
@@ -20,35 +20,44 @@ import Text.InterpolatedString.Perl6 (q)
 import Protolude

 queryPgVersion :: Session PgVersion
-queryPgVersion = statement mempty $ SQL.Statement sql HE.noParams versionRow False
+queryPgVersion = statement mempty pgVersionStatement
+
+pgVersionStatement :: SQL.Statement () PgVersion
+pgVersionStatement = SQL.Statement sql HE.noParams versionRow False
  where
    sql = "SELECT current_setting('server_version_num')::integer, current_setting('server_version')"
    versionRow = HD.singleRow $ PgVersion <$> column HD.int4 <*> column HD.text

-queryDbSettings :: SQL.Pool -> Bool -> IO (Either SQL.UsageError [(Text, Text)])
-queryDbSettings pool prepared =
+queryDbSettings :: Bool -> Session [(Text, Text)]
+queryDbSettings prepared =
  let transaction = if prepared then SQL.transaction else SQL.unpreparedTransaction in
-  SQL.use pool . transaction SQL.ReadCommitted SQL.Read $
-    SQL.statement mempty dbSettingsStatement
+  transaction SQL.ReadCommitted SQL.Read $ SQL.statement mempty dbSettingsStatement

 -- | Get db settings from the connection role. Global settings will be overridden by database specific settings.
 dbSettingsStatement :: SQL.Statement () [(Text, Text)]
 dbSettingsStatement = SQL.Statement sql HE.noParams decodeSettings False
  where
    sql = [q|
-      with
-      role_setting as (
-        select setdatabase, unnest(setconfig) as setting from pg_catalog.pg_db_role_setting
-        where setrole = current_user::regrole::oid
-          and setdatabase in (0, (select oid from pg_catalog.pg_database where datname = current_catalog))
+      WITH
+      role_setting (database, setting) AS (
+        SELECT setdatabase,
+               unnest(setconfig)
+          FROM pg_catalog.pg_db_role_setting
+         WHERE setrole = CURRENT_USER::regrole::oid
+           AND setdatabase IN (0, (SELECT oid FROM pg_catalog.pg_database WHERE datname = CURRENT_CATALOG))
      ),
-      kv_settings as (
-        select setdatabase, split_part(setting, '=', 1) as k, split_part(setting, '=', 2) as value from role_setting
-        where setting like 'pgrst.%'
+      kv_settings (database, k, v) AS (
+        SELECT database,
+               substr(setting, 1, strpos(setting, '=') - 1),
+               substr(setting, strpos(setting, '=') + 1)
+          FROM role_setting
+         WHERE setting LIKE 'pgrst.%'
      )
-      select distinct on (key) replace(k, 'pgrst.', '') as key, value
-      from kv_settings
-      order by key, setdatabase desc;
+      SELECT DISTINCT ON (key)
+             replace(k, 'pgrst.', '') AS key,
+             v AS value
+        FROM kv_settings
+       ORDER BY key, database DESC;
    |]
    decodeSettings = HD.rowList $ (,) <$> column HD.text <*> column HD.text

@@ -9,6 +9,7 @@ module PostgREST.Config.PgVersion
  , pgVersion110
  , pgVersion112
  , pgVersion114
+  , pgVersion120
  , pgVersion121
  , pgVersion130
  , pgVersion140
@@ -50,6 +51,9 @@ pgVersion112 = PgVersion 110002 "11.2"
 pgVersion114 :: PgVersion
 pgVersion114 = PgVersion 110004 "11.4"

+pgVersion120 :: PgVersion
+pgVersion120 = PgVersion 120000 "12.0"
+
 pgVersion121 :: PgVersion
 pgVersion121 = PgVersion 120001 "12.1"

@@ -1,64 +0,0 @@
-{-# LANGUAGE DuplicateRecordFields #-}
-
-module PostgREST.ContentType
-  ( ContentType(..)
-  , toHeader
-  , toMime
-  , decodeContentType
-  ) where
-
-import qualified Data.ByteString          as BS
-import qualified Data.ByteString.Internal as BS (c2w)
-
-import Network.HTTP.Types.Header (Header, hContentType)
-
-import Protolude
-
-- | Enumeration of currently supported response content types
-data ContentType
-  = CTApplicationJSON
-  | CTSingularJSON
-  | CTTextCSV
-  | CTTextPlain
-  | CTOpenAPI
-  | CTUrlEncoded
-  | CTOctetStream
-  | CTAny
-  | CTOther ByteString
-  deriving (Eq)
-
-- | Convert from ContentType to a full HTTP Header
-toHeader :: ContentType -> Header
-toHeader ct = (hContentType, toMime ct <> charset)
-  where
-    charset = case ct of
-      CTOctetStream -> mempty
-      CTOther _     -> mempty
-      _             -> "; charset=utf-8"
-
-- | Convert from ContentType to a ByteString representing the mime type
-toMime :: ContentType -> ByteString
-toMime CTApplicationJSON = "application/json"
-toMime CTTextCSV         = "text/csv"
-toMime CTTextPlain       = "text/plain"
-toMime CTOpenAPI         = "application/openapi+json"
-toMime CTSingularJSON    = "application/vnd.pgrst.object+json"
-toMime CTUrlEncoded      = "application/x-www-form-urlencoded"
-toMime CTOctetStream     = "application/octet-stream"
-toMime CTAny             = "*/*"
-toMime (CTOther ct)      = ct
-
-- | Convert from ByteString to ContentType. Warning: discards MIME parameters
-decodeContentType :: BS.ByteString -> ContentType
-decodeContentType ct =
-  case BS.takeWhile (/= BS.c2w ';') ct of
-    "application/json"                  -> CTApplicationJSON
-    "text/csv"                          -> CTTextCSV
-    "text/plain"                        -> CTTextPlain
-    "application/openapi+json"          -> CTOpenAPI
-    "application/vnd.pgrst.object+json" -> CTSingularJSON
-    "application/vnd.pgrst.object"      -> CTSingularJSON
-    "application/x-www-form-urlencoded" -> CTUrlEncoded
-    "application/octet-stream"          -> CTOctetStream
-    "*/*"                               -> CTAny
-    ct'                                 -> CTOther ct'
@@ -0,0 +1,42 @@
+{-|
+Module      : PostgREST.Cors
+Description : Wai Middleware to set cors policy.
+-}
+module PostgREST.Cors (middleware) where
+
+import qualified Data.ByteString.Char8       as BS
+import qualified Data.CaseInsensitive        as CI
+import qualified Network.Wai                 as Wai
+import qualified Network.Wai.Middleware.Cors as Wai
+
+import Data.List (lookup)
+
+import Protolude
+
+middleware :: Wai.Middleware
+middleware = Wai.cors corsPolicy
+
+-- | CORS policy to be used in by Wai Cors middleware
+corsPolicy :: Wai.Request -> Maybe Wai.CorsResourcePolicy
+corsPolicy req = case lookup "origin" headers of
+  Just origin ->
+    Just Wai.CorsResourcePolicy
+    { Wai.corsOrigins = Just ([origin], True)
+    , Wai.corsMethods = ["GET", "POST", "PATCH", "PUT", "DELETE", "OPTIONS"]
+    , Wai.corsRequestHeaders = "Authorization" : accHeaders
+    , Wai.corsExposedHeaders = Just
+      [ "Content-Encoding", "Content-Location", "Content-Range", "Content-Type"
+      , "Date", "Location", "Server", "Transfer-Encoding", "Range-Unit"]
+    , Wai.corsMaxAge = Just $ 60*60*24
+    , Wai.corsVaryOrigin = False
+    , Wai.corsRequireOrigin = False
+    , Wai.corsIgnoreFailures = True
+    }
+  Nothing -> Nothing
+  where
+    headers = Wai.requestHeaders req
+    accHeaders = case lookup "access-control-request-headers" headers of
+      Just hdrs -> map (CI.mk . BS.strip) $ BS.split ',' hdrs
+       -- Impossible case, Middleware.Cors will not evaluate this when
+       -- the Access-Control-Request-Headers header is not set.
+      Nothing   -> []
@@ -1,924 +0,0 @@
-{-|
-Module      : PostgREST.DbStructure
-Description : PostgREST schema cache
-
-This module contains queries that target PostgreSQL system catalogs, these are used to build the schema cache(DbStructure).
-
-The schema cache is necessary for resource embedding, foreign keys are used for inferring the relationships between tables.
-
-These queries are executed once at startup or when PostgREST is reloaded.
-}
-{-# LANGUAGE DeriveAnyClass        #-}
-{-# LANGUAGE DeriveGeneric         #-}
-{-# LANGUAGE FlexibleContexts      #-}
-{-# LANGUAGE MultiParamTypeClasses #-}
-{-# LANGUAGE NamedFieldPuns        #-}
-{-# LANGUAGE QuasiQuotes           #-}
-{-# LANGUAGE RecordWildCards       #-}
-{-# LANGUAGE ScopedTypeVariables   #-}
-{-# LANGUAGE TypeSynonymInstances  #-}
-
-module PostgREST.DbStructure
-  ( DbStructure(..)
-  , queryDbStructure
-  , accessibleTables
-  , accessibleProcs
-  , schemaDescription
-  , tableCols
-  , tablePKCols
-  ) where
-
-import qualified Data.Aeson          as JSON
-import qualified Data.HashMap.Strict as M
-import qualified Data.List           as L
-import qualified Hasql.Decoders      as HD
-import qualified Hasql.Encoders      as HE
-import qualified Hasql.Statement     as SQL
-import qualified Hasql.Transaction   as SQL
-
-import Contravariant.Extras          (contrazip2)
-import Data.Set                      as S (fromList)
-import Data.Text                     (split)
-import Text.InterpolatedString.Perl6 (q)
-
-import PostgREST.Config.PgVersion         (PgVersion, pgVersion100)
-import PostgREST.DbStructure.Identifiers  (QualifiedIdentifier (..),
-                                           Schema, TableName)
-import PostgREST.DbStructure.Proc         (PgType (..),
-                                           ProcDescription (..),
-                                           ProcParam (..),
-                                           ProcVolatility (..),
-                                           ProcsMap, RetType (..))
-import PostgREST.DbStructure.Relationship (Cardinality (..),
-                                           Junction (..),
-                                           PrimaryKey (..),
-                                           Relationship (..))
-import PostgREST.DbStructure.Table        (Column (..), Table (..))
-
-import Protolude
-import Protolude.Unsafe (unsafeHead)
-
-
-data DbStructure = DbStructure
-  { dbTables        :: [Table]
-  , dbColumns       :: [Column]
-  , dbRelationships :: [Relationship]
-  , dbPrimaryKeys   :: [PrimaryKey]
-  , dbProcs         :: ProcsMap
-  }
-  deriving (Generic, JSON.ToJSON)
-
-- TODO Table could hold references to all its Columns
-tableCols :: DbStructure -> Schema -> TableName -> [Column]
-tableCols dbs tSchema tName = filter (\Column{colTable=Table{tableSchema=s, tableName=t}} -> s==tSchema && t==tName) $ dbColumns dbs
-
-- TODO Table could hold references to all its PrimaryKeys
-tablePKCols :: DbStructure -> Schema -> TableName -> [Text]
-tablePKCols dbs tSchema tName =  pkName <$> filter (\pk -> tSchema == (tableSchema . pkTable) pk && tName == (tableName . pkTable) pk) (dbPrimaryKeys dbs)
-
-- | The source table column a view column refers to
-type SourceColumn = (Column, ViewColumn)
-type ViewColumn = Column
-
-- | A SQL query that can be executed independently
-type SqlQuery = ByteString
-
-queryDbStructure :: [Schema] -> [Schema] -> PgVersion -> Bool -> SQL.Transaction DbStructure
-queryDbStructure schemas extraSearchPath pgVer prepared = do
-  SQL.sql "set local schema ''" -- This voids the search path. The following queries need this for getting the fully qualified name(schema.name) of every db object
-  tabs    <- SQL.statement mempty $ allTables pgVer prepared
-  cols    <- SQL.statement schemas $ allColumns tabs prepared
-  srcCols <- SQL.statement (schemas, extraSearchPath) $ pfkSourceColumns cols prepared
-  m2oRels <- SQL.statement mempty $ allM2ORels tabs cols prepared
-  keys    <- SQL.statement mempty $ allPrimaryKeys tabs prepared
-  procs   <- SQL.statement schemas $ allProcs prepared
-
-  let rels = addO2MRels . addM2MRels $ addViewM2ORels srcCols m2oRels
-      keys' = addViewPrimaryKeys srcCols keys
-
-  return $ removeInternal schemas $ DbStructure {
-      dbTables = tabs
-    , dbColumns = cols
-    , dbRelationships = rels
-    , dbPrimaryKeys = keys'
-    , dbProcs = procs
-    }
-
-- | Remove db objects that belong to an internal schema(not exposed through the API) from the DbStructure.
-removeInternal :: [Schema] -> DbStructure -> DbStructure
-removeInternal schemas dbStruct =
-  DbStructure {
-      dbTables        = filter (\x -> tableSchema x `elem` schemas) $ dbTables dbStruct
-    , dbColumns       = filter (\x -> tableSchema (colTable x) `elem` schemas) (dbColumns dbStruct)
-    , dbRelationships = filter (\x -> tableSchema (relTable x) `elem` schemas &&
-                                      tableSchema (relForeignTable x) `elem` schemas &&
-                                      not (hasInternalJunction x)) $ dbRelationships dbStruct
-    , dbPrimaryKeys   = filter (\x -> tableSchema (pkTable x) `elem` schemas) $ dbPrimaryKeys dbStruct
-    , dbProcs         = dbProcs dbStruct -- procs are only obtained from the exposed schemas, no need to filter them.
-    }
-  where
-    hasInternalJunction rel = case relCardinality rel of
-      M2M Junction{junTable} -> tableSchema junTable `notElem` schemas
-      _                      -> False
-
-decodeTables :: HD.Result [Table]
-decodeTables =
-  HD.rowList tblRow
- where
-  tblRow = Table <$> column HD.text
-                 <*> column HD.text
-                 <*> nullableColumn HD.text
-                 <*> column HD.bool
-                 <*> column HD.bool
-                 <*> column HD.bool
-
-decodeColumns :: [Table] -> HD.Result [Column]
-decodeColumns tables =
-  mapMaybe (columnFromRow tables) <$> HD.rowList colRow
- where
-  colRow =
-    (,,,,,,,,)
-      <$> column HD.text
-      <*> column HD.text
-      <*> column HD.text
-      <*> nullableColumn HD.text
-      <*> column HD.bool
-      <*> column HD.text
-      <*> nullableColumn HD.int4
-      <*> nullableColumn HD.text
-      <*> nullableColumn HD.text
-
-decodeRels :: [Table] -> [Column] -> HD.Result [Relationship]
-decodeRels tables cols =
-  mapMaybe (relFromRow tables cols) <$> HD.rowList relRow
- where
-  relRow = (,,,,,,)
-    <$> column HD.text
-    <*> column HD.text
-    <*> column HD.text
-    <*> arrayColumn HD.text
-    <*> column HD.text
-    <*> column HD.text
-    <*> arrayColumn HD.text
-
-decodePks :: [Table] -> HD.Result [PrimaryKey]
-decodePks tables =
-  mapMaybe (pkFromRow tables) <$> HD.rowList pkRow
- where
-  pkRow = (,,) <$> column HD.text <*> column HD.text <*> column HD.text
-
-decodeSourceColumns :: [Column] -> HD.Result [SourceColumn]
-decodeSourceColumns cols =
-  mapMaybe (sourceColumnFromRow cols) <$> HD.rowList srcColRow
- where
-  srcColRow = (,,,,,)
-    <$> column HD.text <*> column HD.text
-    <*> column HD.text <*> column HD.text
-    <*> column HD.text <*> column HD.text
-
-sourceColumnFromRow :: [Column] -> (Text,Text,Text,Text,Text,Text) -> Maybe SourceColumn
-sourceColumnFromRow allCols (s1,t1,c1,s2,t2,c2) = (,) <$> col1 <*> col2
-  where
-    col1 = findCol s1 t1 c1
-    col2 = findCol s2 t2 c2
-    findCol s t c = find (\col -> (tableSchema . colTable) col == s && (tableName . colTable) col == t && colName col == c) allCols
-
-decodeProcs :: HD.Result ProcsMap
-decodeProcs =
-  -- Duplicate rows for a function means they're overloaded, order these by least args according to ProcDescription Ord instance
-  map sort . M.fromListWith (++) . map ((\(x,y) -> (x, [y])) . addKey) <$> HD.rowList procRow
-  where
-    procRow = ProcDescription
-              <$> column HD.text
-              <*> column HD.text
-              <*> nullableColumn HD.text
-              <*> compositeArrayColumn
-                  (ProcParam
-                  <$> compositeField HD.text
-                  <*> compositeField HD.text
-                  <*> compositeField HD.bool
-                  <*> compositeField HD.bool)
-              <*> (parseRetType
-                  <$> column HD.text
-                  <*> column HD.text
-                  <*> column HD.bool
-                  <*> column HD.bool)
-              <*> (parseVolatility <$> column HD.char)
-              <*> column HD.bool
-
-    addKey :: ProcDescription -> (QualifiedIdentifier, ProcDescription)
-    addKey pd = (QualifiedIdentifier (pdSchema pd) (pdName pd), pd)
-
-    parseRetType :: Text -> Text -> Bool -> Bool -> RetType
-    parseRetType schema name isSetOf isComposite
-      | isSetOf   = SetOf pgType
-      | otherwise = Single pgType
-      where
-        qi = QualifiedIdentifier schema name
-        pgType
-          | isComposite = Composite qi
-          | otherwise   = Scalar
-
-    parseVolatility :: Char -> ProcVolatility
-    parseVolatility v | v == 'i' = Immutable
-                      | v == 's' = Stable
-                      | otherwise = Volatile -- only 'v' can happen here
-
-allProcs :: Bool -> SQL.Statement [Schema] ProcsMap
-allProcs = SQL.Statement sql (arrayParam HE.text) decodeProcs
-  where
-    sql = procsSqlQuery <> " WHERE pn.nspname = ANY($1)"
-
-accessibleProcs :: Bool -> SQL.Statement Schema ProcsMap
-accessibleProcs = SQL.Statement sql (param HE.text) decodeProcs
-  where
-    sql = procsSqlQuery <> " WHERE pn.nspname = $1 AND has_function_privilege(p.oid, 'execute')"
-
-procsSqlQuery :: SqlQuery
-procsSqlQuery = [q|
- -- Recursively get the base types of domains
-  WITH
-  base_types AS (
-    WITH RECURSIVE
-    recurse AS (
-      SELECT
-        oid,
-        typbasetype,
-        COALESCE(NULLIF(typbasetype, 0), oid) AS base
-      FROM pg_type
-      UNION
-      SELECT
-        t.oid,
-        b.typbasetype,
-        COALESCE(NULLIF(b.typbasetype, 0), b.oid) AS base
-      FROM recurse t
-      JOIN pg_type b ON t.typbasetype = b.oid
-    )
-    SELECT
-      oid,
-      base
-    FROM recurse
-    WHERE typbasetype = 0
-  ),
-  arguments AS (
-    SELECT
-      oid,
-      array_agg((
-        COALESCE(name, ''), -- name
-        type::regtype::text, -- type
-        idx <= (pronargs - pronargdefaults), -- is_required
-        COALESCE(mode = 'v', FALSE) -- is_variadic
-      ) ORDER BY idx) AS args
-    FROM pg_proc,
-         unnest(proargnames, proargtypes, proargmodes)
-           WITH ORDINALITY AS _ (name, type, mode, idx)
-    WHERE type IS NOT NULL -- only input arguments
-    GROUP BY oid
-  )
-  SELECT
-    pn.nspname AS proc_schema,
-    p.proname AS proc_name,
-    d.description AS proc_description,
-    COALESCE(a.args, '{}') AS args,
-    tn.nspname AS schema,
-    COALESCE(comp.relname, t.typname) AS name,
-    p.proretset AS rettype_is_setof,
-    (t.typtype = 'c'
-     -- if any TABLE, INOUT or OUT arguments present, treat as composite
-     or COALESCE(proargmodes::text[] && '{t,b,o}', false)
-    ) AS rettype_is_composite,
-    p.provolatile,
-    p.provariadic > 0 as hasvariadic
-  FROM pg_proc p
-  LEFT JOIN arguments a ON a.oid = p.oid
-  JOIN pg_namespace pn ON pn.oid = p.pronamespace
-  JOIN base_types bt ON bt.oid = p.prorettype
-  JOIN pg_type t ON t.oid = bt.base
-  JOIN pg_namespace tn ON tn.oid = t.typnamespace
-  LEFT JOIN pg_class comp ON comp.oid = t.typrelid
-  LEFT JOIN pg_catalog.pg_description as d ON d.objoid = p.oid
-|]
-
-schemaDescription :: Bool -> SQL.Statement Schema (Maybe Text)
-schemaDescription =
-    SQL.Statement sql (param HE.text) (join <$> HD.rowMaybe (nullableColumn HD.text))
-  where
-    sql = [q|
-      select
-        description
-      from
-        pg_catalog.pg_namespace n
-        left join pg_catalog.pg_description d on d.objoid = n.oid
-      where
-        n.nspname = $1 |]
-
-accessibleTables :: PgVersion -> Bool -> SQL.Statement Schema [Table]
-accessibleTables pgVer =
-  SQL.Statement sql (param HE.text) decodeTables
- where
-  sql = [q|
-    select
-      n.nspname as table_schema,
-      relname as table_name,
-      d.description as table_description,
-      (
-        c.relkind IN ('r','p')
-        OR (
-          c.relkind IN ('v','f')
-          -- CMD_INSERT - see allTables query below for explanation
-          AND (pg_relation_is_updatable(c.oid::regclass, TRUE) & 8) = 8
-        )
-      ) AS insertable,
-      (
-        c.relkind IN ('r','p')
-        OR (
-          c.relkind IN ('v','f')
-          -- CMD_UPDATE
-          AND (pg_relation_is_updatable(c.oid::regclass, TRUE) & 4) = 4
-        )
-      ) as updatable,
-      (
-        c.relkind IN ('r','p')
-        OR (
-          c.relkind IN ('v','f')
-          -- CMD_DELETE
-          AND (pg_relation_is_updatable(c.oid::regclass, TRUE) & 16) = 16
-        )
-      ) as deletable
-    from
-      pg_class c
-      join pg_namespace n on n.oid = c.relnamespace
-      left join pg_catalog.pg_description as d on d.objoid = c.oid and d.objsubid = 0
-    where
-      c.relkind in ('v','r','m','f','p')
-      and n.nspname = $1 |]
-      <> relIsNotPartition pgVer <> [q|
-      and (
-        pg_has_role(c.relowner, 'USAGE')
-        or has_table_privilege(c.oid, 'SELECT, INSERT, UPDATE, DELETE, TRUNCATE, REFERENCES, TRIGGER')
-        or has_any_column_privilege(c.oid, 'SELECT, INSERT, UPDATE, REFERENCES')
-      )
-    order by relname |]
-
-{-
-Adds Views M2O Relationships based on SourceColumns found, the logic is as follows:
-
-Having a Relationship{relTable=t1, relColumns=[c1], relFTable=t2, relFColumns=[c2], relCardinality=M2O} represented by:
-
-t1.c1------t2.c2
-
-When only having a t1_view.c1 source column, we need to add a View-Table M2O Relationship
-
-         t1.c1----t2.c2         t1.c1----------t2.c2
-                         ->            ________/
-                                      /
-      t1_view.c1             t1_view.c1
-
-
-When only having a t2_view.c2 source column, we need to add a Table-View M2O Relationship
-
-         t1.c1----t2.c2               t1.c1----------t2.c2
-                               ->          \________
-                                                    \
-                    t2_view.c2                      t2_view.c1
-
-When having t1_view.c1 and a t2_view.c2 source columns, we need to add a View-View M2O Relationship in addition to the prior
-
-         t1.c1----t2.c2               t1.c1----------t2.c2
-                               ->          \________/
-                                           /        \
-    t1_view.c1     t2_view.c2     t1_view.c1-------t2_view.c1
-
-The logic for composite pks is similar just need to make sure all the Relationship columns have source columns.
-}
-addViewM2ORels :: [SourceColumn] -> [Relationship] -> [Relationship]
-addViewM2ORels allSrcCols = concatMap (\rel@Relationship{..} -> rel :
-  let
-    srcColsGroupedByView :: [Column] -> [[SourceColumn]]
-    srcColsGroupedByView relCols = L.groupBy (\(_, viewCol1) (_, viewCol2) -> colTable viewCol1 == colTable viewCol2) $
-                   filter (\(c, _) -> c `elem` relCols) allSrcCols
-    relSrcCols = srcColsGroupedByView relColumns
-    relFSrcCols = srcColsGroupedByView relForeignColumns
-    getView :: [SourceColumn] -> Table
-    getView = colTable . snd . unsafeHead
-    srcCols `allSrcColsOf` cols = S.fromList (fst <$> srcCols) == S.fromList cols
-    -- Relationship is dependent on the order of relColumns and relFColumns to get the join conditions right in the generated query.
-    -- So we need to change the order of the SourceColumns to match the relColumns
-    -- TODO: This could be avoided if the Relationship type is improved with a structure that maintains the association of relColumns and relFColumns
-    srcCols `sortAccordingTo` cols = sortOn (\(k, _) -> L.lookup k $ zip cols [0::Int ..]) srcCols
-
-    viewTableM2O =
-      [ Relationship
-          (getView srcCols) (snd <$> srcCols `sortAccordingTo` relColumns)
-          relForeignTable relForeignColumns relCardinality
-      | srcCols <- relSrcCols, srcCols `allSrcColsOf` relColumns ]
-
-    tableViewM2O =
-      [ Relationship
-          relTable relColumns
-          (getView fSrcCols) (snd <$> fSrcCols `sortAccordingTo` relForeignColumns)
-          relCardinality
-      | fSrcCols <- relFSrcCols, fSrcCols `allSrcColsOf` relForeignColumns ]
-
-    viewViewM2O =
-      [ Relationship
-          (getView srcCols) (snd <$> srcCols `sortAccordingTo` relColumns)
-          (getView fSrcCols) (snd <$> fSrcCols `sortAccordingTo` relForeignColumns)
-          relCardinality
-      | srcCols  <- relSrcCols, srcCols `allSrcColsOf` relColumns
-      , fSrcCols <- relFSrcCols, fSrcCols `allSrcColsOf` relForeignColumns ]
-
-  in viewTableM2O ++ tableViewM2O ++ viewViewM2O)
-
-addO2MRels :: [Relationship] -> [Relationship]
-addO2MRels rels = rels ++ [ Relationship ft fc t c (O2M cons)
-                          | Relationship t c ft fc (M2O cons) <- rels ]
-
-addM2MRels :: [Relationship] -> [Relationship]
-addM2MRels rels = rels ++ [ Relationship t c ft fc (M2M $ Junction jt1 cons1 jc1 cons2 jc2)
-                          | Relationship jt1 jc1 t c (M2O cons1) <- rels
-                          , Relationship jt2 jc2 ft fc (M2O cons2) <- rels
-                          , jt1 == jt2
-                          , cons1 /= cons2]
-
-addViewPrimaryKeys :: [SourceColumn] -> [PrimaryKey] -> [PrimaryKey]
-addViewPrimaryKeys srcCols = concatMap (\pk ->
-  let viewPks = (\(_, viewCol) -> PrimaryKey{pkTable=colTable viewCol, pkName=colName viewCol}) <$>
-                filter (\(col, _) -> colTable col == pkTable pk && colName col == pkName pk) srcCols in
-  pk : viewPks)
-
-allTables :: PgVersion -> Bool -> SQL.Statement () [Table]
-allTables pgVer =
-  SQL.Statement sql HE.noParams decodeTables
- where
-  sql = [q|
-    SELECT
-      n.nspname AS table_schema,
-      c.relname AS table_name,
-      d.description AS table_description,
-      (
-        c.relkind IN ('r','p')
-        OR (
-          c.relkind in ('v','f')
-          -- The function `pg_relation_is_updateable` returns a bitmask where 8
-          -- corresponds to `1 << CMD_INSERT` in the PostgreSQL source code, i.e.
-          -- it's possible to insert into the relation.
-          AND (pg_relation_is_updatable(c.oid::regclass, TRUE) & 8) = 8
-        )
-      ) AS insertable,
-      (
-        c.relkind IN ('r','p')
-        OR (
-          c.relkind in ('v','f')
-          -- CMD_UPDATE
-          AND (pg_relation_is_updatable(c.oid::regclass, TRUE) & 4) = 4
-        )
-      ) AS updatable,
-      (
-        c.relkind IN ('r','p')
-        OR (
-          c.relkind in ('v','f')
-          -- CMD_DELETE
-          AND (pg_relation_is_updatable(c.oid::regclass, TRUE) & 16) = 16
-        )
-      ) AS deletable
-    FROM pg_class c
-    JOIN pg_namespace n ON n.oid = c.relnamespace
-    LEFT JOIN pg_catalog.pg_description as d on d.objoid = c.oid and d.objsubid = 0
-    WHERE c.relkind IN ('v','r','m','f','p')
-      AND n.nspname NOT IN ('pg_catalog', 'information_schema') |]
-      <> relIsNotPartition pgVer <> [q|
-    ORDER BY table_schema, table_name |]
-
-relIsNotPartition :: PgVersion -> SqlQuery
-relIsNotPartition pgVer = if pgVer >= pgVersion100 then " AND not c.relispartition " else mempty
-
-allColumns :: [Table] -> Bool -> SQL.Statement [Schema] [Column]
-allColumns tabs =
- SQL.Statement sql (arrayParam HE.text) (decodeColumns tabs)
- where
-  sql = [q|
-    SELECT DISTINCT
-        info.table_schema AS schema,
-        info.table_name AS table_name,
-        info.column_name AS name,
-        info.description AS description,
-        info.is_nullable::boolean AS nullable,
-        info.data_type AS col_type,
-        info.character_maximum_length AS max_len,
-        info.column_default AS default_value,
-        array_to_string(enum_info.vals, ',') AS enum,
-        info.position
-    FROM (
-        -- CTE based on pg_catalog to get PRIMARY/FOREIGN key and UNIQUE columns outside api schema
-        WITH key_columns AS (
-             SELECT
-               r.oid AS r_oid,
-               c.oid AS c_oid,
-               n.nspname,
-               c.relname,
-               r.conname,
-               r.contype,
-               unnest(r.conkey) AS conkey
-             FROM
-               pg_catalog.pg_constraint r,
-               pg_catalog.pg_class c,
-               pg_catalog.pg_namespace n
-             WHERE
-               r.contype IN ('f', 'p', 'u')
-               AND c.relkind IN ('r', 'v', 'f', 'm', 'p')
-               AND r.conrelid = c.oid
-               AND c.relnamespace = n.oid
-               AND n.nspname <> ANY (ARRAY['pg_catalog', 'information_schema'] || $1)
-        ),
-        /*
-        -- CTE based on information_schema.columns
-        -- changed:
-        -- remove the owner filter
-        -- limit columns to the ones in the api schema or PK/FK columns
-        */
-        columns AS (
-            SELECT
-                nc.nspname::name AS table_schema,
-                c.relname::name AS table_name,
-                a.attname::name AS column_name,
-                d.description AS description,
-                pg_get_expr(ad.adbin, ad.adrelid)::text AS column_default,
-                not (a.attnotnull OR t.typtype = 'd' AND t.typnotnull) AS is_nullable,
-                    CASE
-                        WHEN t.typtype = 'd' THEN
-                        CASE
-                            WHEN bt.typelem <> 0::oid AND bt.typlen = (-1) THEN 'ARRAY'::text
-                            WHEN nbt.nspname = 'pg_catalog'::name THEN format_type(t.typbasetype, NULL::integer)
-                            ELSE format_type(a.atttypid, a.atttypmod)
-                        END
-                        ELSE
-                        CASE
-                            WHEN t.typelem <> 0::oid AND t.typlen = (-1) THEN 'ARRAY'::text
-                            WHEN nt.nspname = 'pg_catalog'::name THEN format_type(a.atttypid, NULL::integer)
-                            ELSE format_type(a.atttypid, a.atttypmod)
-                        END
-                    END::text AS data_type,
-                information_schema._pg_char_max_length(
-                    information_schema._pg_truetypid(a.*, t.*),
-                    information_schema._pg_truetypmod(a.*, t.*)
-                )::integer AS character_maximum_length,
-                COALESCE(bt.typname, t.typname)::name AS udt_name,
-                a.attnum::integer AS position
-            FROM pg_attribute a
-                LEFT JOIN key_columns kc
-                    ON kc.conkey = a.attnum AND kc.c_oid = a.attrelid
-                LEFT JOIN pg_catalog.pg_description AS d
-                    ON d.objoid = a.attrelid and d.objsubid = a.attnum
-                LEFT JOIN pg_attrdef ad
-                    ON a.attrelid = ad.adrelid AND a.attnum = ad.adnum
-                JOIN (pg_class c JOIN pg_namespace nc ON c.relnamespace = nc.oid)
-                    ON a.attrelid = c.oid
-                JOIN (pg_type t JOIN pg_namespace nt ON t.typnamespace = nt.oid)
-                    ON a.atttypid = t.oid
-                LEFT JOIN (pg_type bt JOIN pg_namespace nbt ON bt.typnamespace = nbt.oid)
-                    ON t.typtype = 'd' AND t.typbasetype = bt.oid
-                LEFT JOIN (pg_collation co JOIN pg_namespace nco ON co.collnamespace = nco.oid)
-                    ON a.attcollation = co.oid AND (nco.nspname <> 'pg_catalog'::name OR co.collname <> 'default'::name)
-            WHERE
-                NOT pg_is_other_temp_schema(nc.oid)
-                AND a.attnum > 0
-                AND NOT a.attisdropped
-                AND c.relkind in ('r', 'v', 'f', 'm', 'p')
-                -- Filter only columns that are FK/PK or in the api schema:
-                AND (nc.nspname = ANY ($1) OR kc.r_oid IS NOT NULL)
-        )
-        SELECT
-            table_schema,
-            table_name,
-            column_name,
-            description,
-            is_nullable,
-            data_type,
-            character_maximum_length,
-            column_default,
-            udt_name,
-            position
-        FROM columns
-        WHERE table_schema NOT IN ('pg_catalog', 'information_schema')
-    ) AS info
-    LEFT OUTER JOIN (
-        SELECT
-            n.nspname AS s,
-            t.typname AS n,
-            array_agg(e.enumlabel ORDER BY e.enumsortorder) AS vals
-        FROM pg_type t
-        JOIN pg_enum e ON t.oid = e.enumtypid
-        JOIN pg_catalog.pg_namespace n ON n.oid = t.typnamespace
-        GROUP BY s,n
-    ) AS enum_info ON (info.udt_name = enum_info.n)
-    ORDER BY schema, position |]
-
-columnFromRow :: [Table] ->
-                 (Text,        Text,        Text,
-                  Maybe Text,  Bool,        Text,
-                  Maybe Int32, Maybe Text,  Maybe Text)
-                 -> Maybe Column
-columnFromRow tabs (s, t, n, desc, nul, typ, l, d, e) = buildColumn <$> table
-  where
-    buildColumn tbl = Column tbl n desc nul typ l d (parseEnum e)
-    table = find (\tbl -> tableSchema tbl == s && tableName tbl == t) tabs
-    parseEnum :: Maybe Text -> [Text]
-    parseEnum = maybe [] (split (==','))
-
-allM2ORels :: [Table] -> [Column] -> Bool -> SQL.Statement () [Relationship]
-allM2ORels tabs cols =
-  SQL.Statement sql HE.noParams (decodeRels tabs cols)
- where
-  sql = [q|
-    SELECT ns1.nspname AS table_schema,
-           tab.relname AS table_name,
-           conname     AS constraint_name,
-           column_info.cols AS columns,
-           ns2.nspname AS foreign_table_schema,
-           other.relname AS foreign_table_name,
-           column_info.refs AS foreign_columns
-    FROM pg_constraint,
-    LATERAL (
-      SELECT array_agg(cols.attname) AS cols,
-                    array_agg(cols.attnum)  AS nums,
-                    array_agg(refs.attname) AS refs
-      FROM ( SELECT unnest(conkey) AS col, unnest(confkey) AS ref) k,
-      LATERAL (SELECT * FROM pg_attribute WHERE attrelid = conrelid AND attnum = col) AS cols,
-      LATERAL (SELECT * FROM pg_attribute WHERE attrelid = confrelid AND attnum = ref) AS refs) AS column_info,
-    LATERAL (SELECT * FROM pg_namespace WHERE pg_namespace.oid = connamespace) AS ns1,
-    LATERAL (SELECT * FROM pg_class WHERE pg_class.oid = conrelid) AS tab,
-    LATERAL (SELECT * FROM pg_class WHERE pg_class.oid = confrelid) AS other,
-    LATERAL (SELECT * FROM pg_namespace WHERE pg_namespace.oid = other.relnamespace) AS ns2
-    WHERE confrelid != 0
-    ORDER BY (conrelid, column_info.nums) |]
-
-relFromRow :: [Table] -> [Column] -> (Text, Text, Text, [Text], Text, Text, [Text]) -> Maybe Relationship
-relFromRow allTabs allCols (rs, rt, cn, rcs, frs, frt, frcs) =
-  Relationship <$> table <*> cols <*> tableF <*> colsF <*> pure (M2O cn)
-  where
-    findTable s t = find (\tbl -> tableSchema tbl == s && tableName tbl == t) allTabs
-    findCol s t c = find (\col -> tableSchema (colTable col) == s && tableName (colTable col) == t && colName col == c) allCols
-    table  = findTable rs rt
-    tableF = findTable frs frt
-    cols  = mapM (findCol rs rt) rcs
-    colsF = mapM (findCol frs frt) frcs
-
-allPrimaryKeys :: [Table] -> Bool -> SQL.Statement () [PrimaryKey]
-allPrimaryKeys tabs =
-  SQL.Statement sql HE.noParams (decodePks tabs)
- where
-  sql = [q|
-    -- CTE to replace information_schema.table_constraints to remove owner limit
-    WITH tc AS (
-        SELECT
-            c.conname::name AS constraint_name,
-            nr.nspname::name AS table_schema,
-            r.relname::name AS table_name
-        FROM pg_namespace nc,
-            pg_namespace nr,
-            pg_constraint c,
-            pg_class r
-        WHERE
-            nc.oid = c.connamespace
-            AND nr.oid = r.relnamespace
-            AND c.conrelid = r.oid
-            AND r.relkind IN ('r', 'p')
-            AND NOT pg_is_other_temp_schema(nr.oid)
-            AND c.contype = 'p'
-    ),
-    -- CTE to replace information_schema.key_column_usage to remove owner limit
-    kc AS (
-        SELECT
-            ss.conname::name AS constraint_name,
-            ss.nr_nspname::name AS table_schema,
-            ss.relname::name AS table_name,
-            a.attname::name AS column_name,
-            (ss.x).n::integer AS ordinal_position,
-            CASE
-                WHEN ss.contype = 'f' THEN information_schema._pg_index_position(ss.conindid, ss.confkey[(ss.x).n])
-                ELSE NULL::integer
-            END::integer AS position_in_unique_constraint
-        FROM pg_attribute a,
-            ( SELECT r.oid AS roid,
-                r.relname,
-                r.relowner,
-                nc.nspname AS nc_nspname,
-                nr.nspname AS nr_nspname,
-                c.oid AS coid,
-                c.conname,
-                c.contype,
-                c.conindid,
-                c.confkey,
-                information_schema._pg_expandarray(c.conkey) AS x
-               FROM pg_namespace nr,
-                pg_class r,
-                pg_namespace nc,
-                pg_constraint c
-              WHERE
-                nr.oid = r.relnamespace
-                AND r.oid = c.conrelid
-                AND nc.oid = c.connamespace
-                AND c.contype in ('p', 'u', 'f')
-                AND r.relkind IN ('r', 'p')
-                AND NOT pg_is_other_temp_schema(nr.oid)
-            ) ss
-        WHERE
-          ss.roid = a.attrelid
-          AND a.attnum = (ss.x).x
-          AND NOT a.attisdropped
-    )
-    SELECT
-        kc.table_schema,
-        kc.table_name,
-        kc.column_name
-    FROM
-        tc, kc
-    WHERE
-        kc.table_name = tc.table_name AND
-        kc.table_schema = tc.table_schema AND
-        kc.constraint_name = tc.constraint_name AND
-        kc.table_schema NOT IN ('pg_catalog', 'information_schema') |]
-
-pkFromRow :: [Table] -> (Schema, Text, Text) -> Maybe PrimaryKey
-pkFromRow tabs (s, t, n) = PrimaryKey <$> table <*> pure n
-  where table = find (\tbl -> tableSchema tbl == s && tableName tbl == t) tabs
-
-- returns all the primary and foreign key columns which are referenced in views
-pfkSourceColumns :: [Column] -> Bool -> SQL.Statement ([Schema], [Schema]) [SourceColumn]
-pfkSourceColumns cols =
-  SQL.Statement sql (contrazip2 (arrayParam HE.text) (arrayParam HE.text)) (decodeSourceColumns cols)
-  -- query explanation at:
-  --  * rationale: https://gist.github.com/wolfgangwalther/5425d64e7b0d20aad71f6f68474d9f19
-  --  * json transformation: https://gist.github.com/wolfgangwalther/3a8939da680c24ad767e93ad2c183089
-  where
-    sql = [q|
-      with recursive
-      pks_fks as (
-        -- pk + fk referencing col
-        select
-          conrelid as resorigtbl,
-          unnest(conkey) as resorigcol
-        from pg_constraint
-        where contype IN ('p', 'f')
-        union
-        -- fk referenced col
-        select
-          confrelid,
-          unnest(confkey)
-        from pg_constraint
-        where contype='f'
-      ),
-      views as (
-        select
-          c.oid       as view_id,
-          n.nspname   as view_schema,
-          c.relname   as view_name,
-          r.ev_action as view_definition
-        from pg_class c
-        join pg_namespace n on n.oid = c.relnamespace
-        join pg_rewrite r on r.ev_class = c.oid
-        where c.relkind in ('v', 'm') and n.nspname = ANY($1 || $2)
-      ),
-      transform_json as (
-        select
-          view_id, view_schema, view_name,
-          -- the following formatting is without indentation on purpose
-          -- to allow simple diffs, with less whitespace noise
-          replace(
-            replace(
-            replace(
-            replace(
-            replace(
-            replace(
-            replace(
-            replace(
-            regexp_replace(
-            replace(
-            replace(
-            replace(
-            replace(
-            replace(
-            replace(
-            replace(
-            replace(
-            replace(
-            replace(
-              view_definition::text,
-            -- This conversion to json is heavily optimized for performance.
-            -- The general idea is to use as few regexp_replace() calls as possible.
-            -- Simple replace() is a lot faster, so we jump through some hoops
-            -- to be able to use regexp_replace() only once.
-            -- This has been tested against a huge schema with 250+ different views.
-            -- The unit tests do NOT reflect all possible inputs. Be careful when changing this!
-            -- -----------------------------------------------
-            -- pattern           | replacement         | flags
-            -- -----------------------------------------------
-            -- `,` is not part of the pg_node_tree format, but used in the regex.
-            -- This removes all `,` that might be part of column names.
-               ','               , ''
-            -- The same applies for `{` and `}`, although those are used a lot in pg_node_tree.
-            -- We remove the escaped ones, which might be part of column names again.
-            ), E'\\{'            , ''
-            ), E'\\}'            , ''
-            -- The fields we need are formatted as json manually to protect them from the regex.
-            ), ' :targetList '   , ',"targetList":'
-            ), ' :resno '        , ',"resno":'
-            ), ' :resorigtbl '   , ',"resorigtbl":'
-            ), ' :resorigcol '   , ',"resorigcol":'
-            -- Make the regex also match the node type, e.g. `{QUERY ...`, to remove it in one pass.
-            ), '{'               , '{ :'
-            -- Protect node lists, which start with `({` or `((` from the greedy regex.
-            -- The extra `{` is removed again later.
-            ), '(('              , '{(('
-            ), '({'              , '{({'
-            -- This regex removes all unused fields to avoid the need to format all of them correctly.
-            -- This leads to a smaller json result as well.
-            -- Removal stops at `,` for used fields (see above) and `}` for the end of the current node.
-            -- Nesting can't be parsed correctly with a regex, so we stop at `{` as well and
-            -- add an empty key for the followig node.
-            ), ' :[^}{,]+'       , ',"":'              , 'g'
-            -- For performance, the regex also added those empty keys when hitting a `,` or `}`.
-            -- Those are removed next.
-            ), ',"":}'           , '}'
-            ), ',"":,'           , ','
-            -- This reverses the "node list protection" from above.
-            ), '{('              , '('
-            -- Every key above has been added with a `,` so far. The first key in an object doesn't need it.
-            ), '{,'              , '{'
-            -- pg_node_tree has `()` around lists, but JSON uses `[]`
-            ), '('               , '['
-            ), ')'               , ']'
-            -- pg_node_tree has ` ` between list items, but JSON uses `,`
-            ), ' '             , ','
-            -- `<>` in pg_node_tree is the same as `null` in JSON, but due to very poor performance of json_typeof
-            -- we need to make this an empty array here to prevent json_array_elements from throwing an error
-            -- when the targetList is null.
-            ), '<>'              , '[]'
-          )::json as view_definition
-        from views
-      ),
-      target_entries as(
-        select
-          view_id, view_schema, view_name,
-          json_array_elements(view_definition->0->'targetList') as entry
-        from transform_json
-      ),
-      results as(
-        select
-          view_id, view_schema, view_name,
-          (entry->>'resno')::int as view_column,
-          (entry->>'resorigtbl')::oid as resorigtbl,
-          (entry->>'resorigcol')::int as resorigcol
-        from target_entries
-      ),
-      recursion as(
-        select r.*
-        from results r
-        where view_schema = ANY ($1)
-        union all
-        select
-          view.view_id,
-          view.view_schema,
-          view.view_name,
-          view.view_column,
-          tab.resorigtbl,
-          tab.resorigcol
-        from recursion view
-        join results tab on view.resorigtbl=tab.view_id and view.resorigcol=tab.view_column
-      )
-      select
-        sch.nspname as table_schema,
-        tbl.relname as table_name,
-        col.attname as table_column_name,
-        rec.view_schema,
-        rec.view_name,
-        vcol.attname as view_column_name
-      from recursion rec
-      join pg_class tbl on tbl.oid = rec.resorigtbl
-      join pg_attribute col on col.attrelid = tbl.oid and col.attnum = rec.resorigcol
-      join pg_attribute vcol on vcol.attrelid = rec.view_id and vcol.attnum = rec.view_column
-      join pg_namespace sch on sch.oid = tbl.relnamespace
-      join pks_fks using (resorigtbl, resorigcol)
-      order by view_schema, view_name, view_column_name; |]
-
-param :: HE.Value a -> HE.Params a
-param = HE.param . HE.nonNullable
-
-arrayParam :: HE.Value a -> HE.Params [a]
-arrayParam = param . HE.foldableArray . HE.nonNullable
-
-compositeArrayColumn :: HD.Composite a -> HD.Row [a]
-compositeArrayColumn = arrayColumn . HD.composite
-
-compositeField :: HD.Value a -> HD.Composite a
-compositeField = HD.field . HD.nonNullable
-
-column :: HD.Value a -> HD.Row a
-column = HD.column . HD.nonNullable
-
-nullableColumn :: HD.Value a -> HD.Row (Maybe a)
-nullableColumn = HD.column . HD.nullable
-
-arrayColumn :: HD.Value a -> HD.Row [a]
-arrayColumn = column . HD.listArray . HD.nonNullable
@@ -1,62 +0,0 @@
-{-# LANGUAGE DeriveAnyClass #-}
-{-# LANGUAGE DeriveGeneric  #-}
-
-module PostgREST.DbStructure.Relationship
-  ( Cardinality(..)
-  , PrimaryKey(..)
-  , Relationship(..)
-  , Junction(..)
-  , isSelfReference
-  ) where
-
-import qualified Data.Aeson as JSON
-
-import PostgREST.DbStructure.Table (Column (..), Table (..))
-
-import Protolude
-
-
-- | Relationship between two tables.
--
-- The order of the relColumns and relForeignColumns should be maintained to get the
-- join conditions right.
--
-- TODO merge relColumns and relForeignColumns to a tuple or Data.Bimap
-data Relationship = Relationship
-  { relTable          :: Table
-  , relColumns        :: [Column]
-  , relForeignTable   :: Table
-  , relForeignColumns :: [Column]
-  , relCardinality    :: Cardinality
-  }
-  deriving (Eq, Generic, JSON.ToJSON)
-
-- | The relationship cardinality
-- | https://en.wikipedia.org/wiki/Cardinality_(data_modeling)
-- TODO: missing one-to-one
-data Cardinality
-  = O2M FKConstraint -- ^ one-to-many cardinality
-  | M2O FKConstraint -- ^ many-to-one cardinality
-  | M2M Junction     -- ^ many-to-many cardinality
-  deriving (Eq, Generic, JSON.ToJSON)
-
-type FKConstraint = Text
-
-- | Junction table on an M2M relationship
-data Junction = Junction
-  { junTable       :: Table
-  , junConstraint1 :: FKConstraint
-  , junColumns1    :: [Column]
-  , junConstraint2 :: FKConstraint
-  , junColumns2    :: [Column]
-  }
-  deriving (Eq, Generic, JSON.ToJSON)
-
-isSelfReference :: Relationship -> Bool
-isSelfReference r = relTable r == relForeignTable r
-
-data PrimaryKey = PrimaryKey
-  { pkTable :: Table
-  , pkName  :: Text
-  }
-  deriving (Generic, JSON.ToJSON)
@@ -17,6 +17,8 @@ module PostgREST.Error

 import qualified Data.Aeson                as JSON
 import qualified Data.ByteString.Char8     as BS
+import qualified Data.FuzzySet             as Fuzzy
+import qualified Data.HashMap.Strict       as HM
 import qualified Data.Text                 as T
 import qualified Data.Text.Encoding        as T
 import qualified Data.Text.Encoding.Error  as T
@@ -29,16 +31,20 @@ import Network.Wai (Response, responseLBS)

 import Network.HTTP.Types.Header (Header)

-import           PostgREST.ContentType (ContentType (..))
-import qualified PostgREST.ContentType as ContentType
+import           PostgREST.ApiRequest.Types (ApiRequestError (..),
+                                             QPError (..),
+                                             RangeError (..))
+import           PostgREST.MediaType        (MediaType (..))
+import qualified PostgREST.MediaType        as MediaType

-import PostgREST.DbStructure.Proc         (ProcDescription (..),
+import PostgREST.SchemaCache.Identifiers  (QualifiedIdentifier (..),
+                                           Schema)
+import PostgREST.SchemaCache.Proc         (ProcDescription (..),
                                           ProcParam (..))
-import PostgREST.DbStructure.Relationship (Cardinality (..),
+import PostgREST.SchemaCache.Relationship (Cardinality (..),
                                           Junction (..),
-                                           Relationship (..))
-import PostgREST.DbStructure.Table        (Column (..), Table (..))
-
+                                           Relationship (..),
+                                           RelationshipsMap)
 import Protolude


@@ -52,108 +58,279 @@ class (JSON.ToJSON a) => PgrstError a where
  errorResponseFor :: a -> Response
  errorResponseFor err = responseLBS (status err) (headers err) $ errorPayload err

-
-
-data ApiRequestError
-  = ActionInappropriate
-  | InvalidRange
-  | InvalidBody ByteString
-  | ParseRequestError Text Text
-  | NoRelBetween Text Text
-  | AmbiguousRelBetween Text Text [Relationship]
-  | AmbiguousRpc [ProcDescription]
-  | NoRpc Text Text [Text] Bool ContentType Bool
-  | InvalidFilters
-  | UnacceptableSchema [Text]
-  | ContentTypeError [ByteString]
-  | UnsupportedVerb                -- Unreachable?
-
 instance PgrstError ApiRequestError where
-  status InvalidRange            = HTTP.status416
-  status InvalidFilters          = HTTP.status405
-  status (InvalidBody _)         = HTTP.status400
-  status UnsupportedVerb         = HTTP.status405
-  status ActionInappropriate     = HTTP.status405
-  status (ParseRequestError _ _) = HTTP.status400
-  status (NoRelBetween _ _)      = HTTP.status400
  status AmbiguousRelBetween{}   = HTTP.status300
-  status (AmbiguousRpc _)        = HTTP.status300
+  status AmbiguousRpc{}          = HTTP.status300
+  status BinaryFieldError{}      = HTTP.status406
+  status MediaTypeError{}        = HTTP.status415
+  status InvalidBody{}           = HTTP.status400
+  status InvalidFilters          = HTTP.status405
+  status InvalidRpcMethod{}      = HTTP.status405
+  status InvalidRange{}          = HTTP.status416
+  status NotFound                = HTTP.status404
+  status NoRelBetween{}          = HTTP.status400
  status NoRpc{}                 = HTTP.status404
-  status (UnacceptableSchema _)  = HTTP.status406
-  status (ContentTypeError _)    = HTTP.status415
+  status NotEmbedded{}           = HTTP.status400
+  status ParseRequestError{}     = HTTP.status400
+  status PutRangeNotAllowedError = HTTP.status400
+  status QueryParamError{}       = HTTP.status400
+  status UnacceptableSchema{}    = HTTP.status406
+  status UnsupportedMethod{}     = HTTP.status405
+  status LimitNoOrderError       = HTTP.status400

-  headers _ = [ContentType.toHeader CTApplicationJSON]
+  headers _ = [MediaType.toContentType MTApplicationJSON]

 instance JSON.ToJSON ApiRequestError where
-  toJSON (ParseRequestError message details) = JSON.object [
-    "message" .= message, "details" .= details]
-  toJSON ActionInappropriate = JSON.object [
-    "message" .= ("Bad Request" :: Text)]
+  toJSON (QueryParamError (QPError message details)) = JSON.object [
+    "code"    .= ApiRequestErrorCode00,
+    "message" .= message,
+    "details" .= details,
+    "hint"    .= JSON.Null]
+  toJSON (InvalidRpcMethod method) = JSON.object [
+    "code"    .= ApiRequestErrorCode01,
+    "message" .= ("Cannot use the " <> T.decodeUtf8 method <> " method on RPC"),
+    "details" .= JSON.Null,
+    "hint"    .= JSON.Null]
  toJSON (InvalidBody errorMessage) = JSON.object [
-    "message" .= T.decodeUtf8 errorMessage]
-  toJSON InvalidRange = JSON.object [
-    "message" .= ("HTTP Range error" :: Text)]
-  toJSON (NoRelBetween parent child) = JSON.object [
-    "hint"    .= ("If a new foreign key between these entities was created in the database, try reloading the schema cache." :: Text),
-    "message" .= ("Could not find a relationship between " <> parent <> " and " <> child <> " in the schema cache" :: Text)]
-  toJSON (AmbiguousRelBetween parent child rels) = JSON.object [
-    "hint"    .= ("Try changing '" <> child <> "' to one of the following: " <> relHint rels <> ". Find the desired relationship in the 'details' key." :: Text),
-    "message" .= ("Could not embed because more than one relationship was found for '" <> parent <> "' and '" <> child <> "'" :: Text),
-    "details" .= (compressedRel <$> rels) ]
-  toJSON (AmbiguousRpc procs)  = JSON.object [
-    "hint"    .= ("Try renaming the parameters or the function itself in the database so function overloading can be resolved" :: Text),
-    "message" .= ("Could not choose the best candidate function between: " <> T.intercalate ", " [pdSchema p <> "." <> pdName p <> "(" <> T.intercalate ", " [ppName a <> " => " <> ppType a | a <- pdParams p] <> ")" | p <- procs])]
-  toJSON (NoRpc schema procName argumentKeys hasPreferSingleObject contentType isInvPost)  =
-    let prms = "(" <> T.intercalate ", " argumentKeys <> ")" in JSON.object [
-    "hint"    .= ("If a new function was created in the database with this name and parameters, try reloading the schema cache." :: Text),
-    "message" .= ("Could not find the " <> schema <> "." <> procName <>
-      (case (hasPreferSingleObject, isInvPost, contentType) of
-        (True, _, _)                 -> " function with a single json or jsonb parameter"
-        (_, True, CTTextPlain)       -> " function with a single unnamed text parameter"
-        (_, True, CTOctetStream)     -> " function with a single unnamed bytea parameter"
-        (_, True, CTApplicationJSON) -> prms <> " function or the " <> schema <> "." <> procName <>" function with a single unnamed json or jsonb parameter"
-        _                            -> prms <> " function") <>
-      " in the schema cache")]
-  toJSON UnsupportedVerb = JSON.object [
-    "message" .= ("Unsupported HTTP verb" :: Text)]
+    "code"    .= ApiRequestErrorCode02,
+    "message" .= T.decodeUtf8 errorMessage,
+    "details" .= JSON.Null,
+    "hint"    .= JSON.Null]
+  toJSON (InvalidRange rangeError) = JSON.object [
+    "code"    .= ApiRequestErrorCode03,
+    "message" .= ("Requested range not satisfiable" :: Text),
+    "details" .= (case rangeError of
+                   NegativeLimit           -> "Limit should be greater than or equal to zero."
+                   LowerGTUpper            -> "The lower boundary must be lower than or equal to the upper boundary in the Range header."
+                   OutOfBounds lower total -> "An offset of " <> lower <> " was requested, but there are only " <> total <> " rows."),
+    "hint"    .= JSON.Null]
+  toJSON (ParseRequestError message details) = JSON.object [
+    "code"    .= ApiRequestErrorCode04,
+    "message" .= message,
+    "details" .= details,
+    "hint"    .= JSON.Null]
  toJSON InvalidFilters = JSON.object [
-    "message" .= ("Filters must include all and only primary key columns with 'eq' operators" :: Text)]
+    "code"    .= ApiRequestErrorCode05,
+    "message" .= ("Filters must include all and only primary key columns with 'eq' operators" :: Text),
+    "details" .= JSON.Null,
+    "hint"    .= JSON.Null]
  toJSON (UnacceptableSchema schemas) = JSON.object [
-    "message" .= ("The schema must be one of the following: " <> T.intercalate ", " schemas)]
-  toJSON (ContentTypeError cts)    = JSON.object [
-    "message" .= ("None of these Content-Types are available: " <> T.intercalate ", " (map T.decodeUtf8 cts))]
+    "code"    .= ApiRequestErrorCode06,
+    "message" .= ("The schema must be one of the following: " <> T.intercalate ", " schemas),
+    "details" .= JSON.Null,
+    "hint"    .= JSON.Null]
+  toJSON (MediaTypeError cts)    = JSON.object [
+    "code"    .= ApiRequestErrorCode07,
+    "message" .= ("None of these media types are available: " <> T.intercalate ", " (map T.decodeUtf8 cts)),
+    "details" .= JSON.Null,
+    "hint"    .= JSON.Null]
+  toJSON NotFound = JSON.object []
+  toJSON (NotEmbedded resource) = JSON.object [
+    "code"    .= ApiRequestErrorCode08,
+    "message" .= ("Cannot apply filter because '" <> resource <> "' is not an embedded resource in this request" :: Text),
+    "details" .= JSON.Null,
+    "hint"    .= ("Verify that '" <> resource <> "' is included in the 'select' query parameter." :: Text)]
+
+  toJSON LimitNoOrderError = JSON.object [
+    "code"    .= ApiRequestErrorCode09,
+    "message" .= ("A 'limit' was applied without an explicit 'order'":: Text),
+    "details" .= JSON.Null,
+    "hint"    .= ("Apply an 'order' using unique column(s)" :: Text)]
+
+  toJSON (BinaryFieldError ct) = JSON.object [
+    "code"    .= ApiRequestErrorCode13,
+    "message" .= ((T.decodeUtf8 (MediaType.toMime ct) <> " requested but more than one column was selected") :: Text),
+    "details" .= JSON.Null,
+    "hint"    .= JSON.Null]
+
+  toJSON PutRangeNotAllowedError = JSON.object [
+    "code"    .= ApiRequestErrorCode14,
+    "message" .= ("Range header and limit/offset querystring parameters are not allowed for PUT" :: Text),
+    "details" .= JSON.Null,
+    "hint"    .= JSON.Null]
+
+  toJSON (UnsupportedMethod method) = JSON.object [
+    "code"    .= ApiRequestErrorCode17,
+    "message" .= ("Unsupported HTTP method: " <> T.decodeUtf8 method),
+    "details" .= JSON.Null,
+    "hint"    .= JSON.Null]
+
+  toJSON (NoRelBetween parent child embedHint schema allRels) = JSON.object [
+    "code"    .= SchemaCacheErrorCode00,
+    "message" .= ("Could not find a relationship between '" <> parent <> "' and '" <> child <> "' in the schema cache" :: Text),
+    "details" .= ("Searched for a foreign key relationship between '" <> parent <> "' and '" <> child <> maybe mempty ("' using the hint '" <>) embedHint <> "' in the schema '" <> schema <> "', but no matches were found."),
+    "hint"    .= noRelBetweenHint parent child schema allRels]
+
+  toJSON (AmbiguousRelBetween parent child rels) = JSON.object [
+    "code"    .= SchemaCacheErrorCode01,
+    "message" .= ("Could not embed because more than one relationship was found for '" <> parent <> "' and '" <> child <> "'" :: Text),
+    "details" .= (compressedRel <$> rels),
+    "hint"    .= ("Try changing '" <> child <> "' to one of the following: " <> relHint rels <> ". Find the desired relationship in the 'details' key." :: Text)]
+  toJSON (NoRpc schema procName argumentKeys hasPreferSingleObject contentType isInvPost allProcs overloadedProcs)  =
+    let func = schema <> "." <> procName
+        prms = T.intercalate ", " argumentKeys
+        prmsMsg = "(" <> prms <> ")"
+        prmsDet = " with parameter" <> (if length argumentKeys > 1 then "s " else " ") <> prms
+        fmtPrms p = if null argumentKeys then " without parameters" else p
+        onlySingleParams = hasPreferSingleObject || (isInvPost && contentType `elem` [MTTextPlain, MTTextXML, MTOctetStream])
+    in JSON.object [
+    "code"    .= SchemaCacheErrorCode02,
+    "message" .= ("Could not find the function " <> func <> (if onlySingleParams then "" else fmtPrms prmsMsg) <> " in the schema cache"),
+    "details" .= ("Searched for the function " <> func <>
+      (case (hasPreferSingleObject, isInvPost, contentType) of
+        (True, _, _)                 -> " with a single json/jsonb parameter"
+        (_, True, MTTextPlain)       -> " with a single unnamed text parameter"
+        (_, True, MTTextXML)         -> " with a single unnamed xml parameter"
+        (_, True, MTOctetStream)     -> " with a single unnamed bytea parameter"
+        (_, True, MTApplicationJSON) -> fmtPrms prmsDet <> " or with a single unnamed json/jsonb parameter"
+        _                            -> fmtPrms prmsDet) <>
+      ", but no matches were found in the schema cache."),
+    -- The hint will be null in the case of single unnamed parameter functions
+    "hint"    .= if onlySingleParams
+                 then Nothing
+                 else noRpcHint schema procName argumentKeys allProcs overloadedProcs ]
+  toJSON (AmbiguousRpc procs)  = JSON.object [
+    "code"    .= SchemaCacheErrorCode03,
+    "message" .= ("Could not choose the best candidate function between: " <> T.intercalate ", " [pdSchema p <> "." <> pdName p <> "(" <> T.intercalate ", " [ppName a <> " => " <> ppType a | a <- pdParams p] <> ")" | p <- procs]),
+    "details" .= JSON.Null,
+    "hint"    .= ("Try renaming the parameters or the function itself in the database so function overloading can be resolved" :: Text)]
+
+-- |
+-- If no relationship is found then:
+--
+-- Looks for parent suggestions if parent not found
+-- Looks for child suggestions if parent is found but child is not
+-- Gives no suggestions if both are found (it means that there is a problem with the embed hint)
+--
+-- >>> :set -Wno-missing-fields
+-- >>> let qi t = QualifiedIdentifier "api" t
+-- >>> let rel ft = Relationship{relForeignTable = qi ft}
+-- >>> let rels = HM.fromList [((qi "films", "api"), [rel "directors", rel "roles", rel "actors"])]
+--
+-- >>> noRelBetweenHint "film" "directors" "api" rels
+-- Just "Perhaps you meant 'films' instead of 'film'."
+--
+-- >>> noRelBetweenHint "films" "role" "api" rels
+-- Just "Perhaps you meant 'roles' instead of 'role'."
+--
+-- >>> noRelBetweenHint "films" "role" "api" rels
+-- Just "Perhaps you meant 'roles' instead of 'role'."
+--
+-- >>> noRelBetweenHint "films" "actors" "api" rels
+-- Nothing
+--
+-- >>> noRelBetweenHint "noclosealternative" "roles" "api" rels
+-- Nothing
+--
+-- >>> noRelBetweenHint "films" "noclosealternative" "api" rels
+-- Nothing
+--
+-- >>> noRelBetweenHint "films" "noclosealternative" "noclosealternative" rels
+-- Nothing
+--
+noRelBetweenHint :: Text -> Text -> Schema -> RelationshipsMap -> Maybe Text
+noRelBetweenHint parent child schema allRels = ("Perhaps you meant '" <>) <$>
+  if isJust findParent
+    then (<> "' instead of '" <> child <> "'.") <$> suggestChild
+    else (<> "' instead of '" <> parent <> "'.") <$> suggestParent
+  where
+    findParent = HM.lookup (QualifiedIdentifier schema parent, schema) allRels
+    fuzzySetOfParents  = Fuzzy.fromList [qiName (fst p) | p <- HM.keys allRels, snd p == schema]
+    fuzzySetOfChildren = Fuzzy.fromList [qiName (relForeignTable c) | c <- fromMaybe [] findParent]
+    suggestParent = Fuzzy.getOne fuzzySetOfParents parent
+    -- Do not give suggestion if the child is found in the relations (weight = 1.0)
+    suggestChild  = headMay [snd k | k <- Fuzzy.get fuzzySetOfChildren child, fst k < 1.0]
+
+-- |
+-- If no function is found with the given name, it does a fuzzy search to all the functions
+-- in the same schema and shows the best match as hint.
+--
+-- >>> :set -Wno-missing-fields
+-- >>> let procs = [(QualifiedIdentifier "api" "test"), (QualifiedIdentifier "api" "another"), (QualifiedIdentifier "private" "other")]
+--
+-- >>> noRpcHint "api" "testt" ["val", "param", "name"] procs []
+-- Just "Perhaps you meant to call the function api.test"
+--
+-- >>> noRpcHint "api" "other" [] procs []
+-- Just "Perhaps you meant to call the function api.another"
+--
+-- >>> noRpcHint "api" "noclosealternative" [] procs []
+-- Nothing
+--
+-- If a function is found with the given name, but no params match, then it does a fuzzy search
+-- to all the overloaded functions' params using the form "param1, param2, param3, ..."
+-- and shows the best match as hint.
+--
+-- >>> let procsDesc = [ProcDescription {pdParams = [ProcParam {ppName="val"}, ProcParam {ppName="param"}, ProcParam {ppName="name"}]}, ProcDescription {pdParams = [ProcParam {ppName="id"}, ProcParam {ppName="attr"}]}]
+--
+-- >>> noRpcHint "api" "test" ["vall", "pqaram", "nam"] procs procsDesc
+-- Just "Perhaps you meant to call the function api.test(name, param, val)"
+--
+-- >>> noRpcHint "api" "test" ["val", "param"] procs procsDesc
+-- Just "Perhaps you meant to call the function api.test(name, param, val)"
+--
+-- >>> noRpcHint "api" "test" ["id", "attrs"] procs procsDesc
+-- Just "Perhaps you meant to call the function api.test(attr, id)"
+--
+-- >>> noRpcHint "api" "test" ["id"] procs procsDesc
+-- Just "Perhaps you meant to call the function api.test(attr, id)"
+--
+-- >>> noRpcHint "api" "test" ["noclosealternative"] procs procsDesc
+-- Nothing
+--
+noRpcHint :: Text -> Text -> [Text] -> [QualifiedIdentifier] -> [ProcDescription] -> Maybe Text
+noRpcHint schema procName params allProcs overloadedProcs =
+  fmap (("Perhaps you meant to call the function " <> schema <> ".") <>) possibleProcs
+  where
+    fuzzySetOfProcs  = Fuzzy.fromList [qiName k | k <- allProcs, qiSchema k == schema]
+    fuzzySetOfParams = Fuzzy.fromList $ listToText <$> [[ppName prm | prm <- pdParams ov] | ov <- overloadedProcs]
+    -- Cannot do a fuzzy search like: Fuzzy.getOne [[Text]] [Text], where [[Text]] is the list of params for each
+    -- overloaded function and [Text] the given params. This converts those lists to text to make fuzzy search possible.
+    -- E.g. ["val", "param", "name"] into "(name, param, val)"
+    listToText       = ("(" <>) . (<> ")") . T.intercalate ", " . sort
+    possibleProcs
+      | null overloadedProcs = Fuzzy.getOne fuzzySetOfProcs procName
+      | otherwise            = (procName <>) <$> Fuzzy.getOne fuzzySetOfParams (listToText params)

 compressedRel :: Relationship -> JSON.Value
+-- An ambiguousness error cannot happen for computed relationships TODO refactor so this mempty is not needed
+compressedRel ComputedRelationship{} = JSON.object mempty
 compressedRel Relationship{..} =
  let
-    fmtTbl Table{..} = tableSchema <> "." <> tableName
-    fmtEls els = "[" <> T.intercalate ", " els <> "]"
+    fmtEls els = "(" <> T.intercalate ", " els <> ")"
  in
  JSON.object $
-    ("embedding" .= (tableName relTable <> " with " <> tableName relForeignTable :: Text))
+    ("embedding" .= (qiName relTable <> " with " <> qiName relForeignTable :: Text))
    : case relCardinality of
        M2M Junction{..} -> [
            "cardinality" .= ("many-to-many" :: Text)
-          , "relationship" .= (fmtTbl junTable <> fmtEls [junConstraint1] <> fmtEls [junConstraint2])
+          , "relationship" .= (qiName junTable <> " using " <> junConstraint1 <> fmtEls (snd <$> junColsSource) <> " and " <> junConstraint2 <> fmtEls (snd <$> junColsTarget))
          ]
-        M2O cons -> [
+        M2O cons relColumns -> [
            "cardinality" .= ("many-to-one" :: Text)
-          , "relationship" .= (cons <> fmtEls (colName <$> relColumns) <> fmtEls (colName <$> relForeignColumns))
+          , "relationship" .= (cons <> " using " <> qiName relTable <> fmtEls (fst <$> relColumns) <> " and " <> qiName relForeignTable <> fmtEls (snd <$> relColumns))
          ]
-        O2M cons -> [
+        O2O cons relColumns -> [
+            "cardinality" .= ("one-to-one" :: Text)
+          , "relationship" .= (cons <> " using " <> qiName relTable <> fmtEls (fst <$> relColumns) <> " and " <> qiName relForeignTable <> fmtEls (snd <$> relColumns))
+          ]
+        O2M cons relColumns -> [
            "cardinality" .= ("one-to-many" :: Text)
-          , "relationship" .= (cons <> fmtEls (colName <$> relColumns) <> fmtEls (colName <$> relForeignColumns))
+          , "relationship" .= (cons <> " using " <> qiName relTable <> fmtEls (fst <$> relColumns) <> " and " <> qiName relForeignTable <> fmtEls (snd <$> relColumns))
          ]

 relHint :: [Relationship] -> Text
 relHint rels = T.intercalate ", " (hintList <$> rels)
  where
    hintList Relationship{..} =
-      let buildHint rel = "'" <> tableName relForeignTable <> "!" <> rel <> "'" in
+      let buildHint rel = "'" <> qiName relForeignTable <> "!" <> rel <> "'" in
      case relCardinality of
-        M2M Junction{..} -> buildHint (tableName junTable)
-        M2O cons         -> buildHint cons
-        O2M cons         -> buildHint cons
+        M2M Junction{..} -> buildHint (qiName junTable)
+        M2O cons _       -> buildHint cons
+        O2O cons _       -> buildHint cons
+        O2M cons _       -> buildHint cons
+    -- An ambiguousness error cannot happen for computed relationships TODO refactor so this mempty is not needed
+    hintList ComputedRelationship{} = mempty

 data PgError = PgError Authenticated SQL.UsageError
 type Authenticated = Bool
@@ -163,61 +340,55 @@ instance PgrstError PgError where

  headers err =
    if status err == HTTP.status401
-       then [ContentType.toHeader CTApplicationJSON, ("WWW-Authenticate", "Bearer") :: Header]
-       else [ContentType.toHeader CTApplicationJSON]
+       then [MediaType.toContentType MTApplicationJSON, ("WWW-Authenticate", "Bearer") :: Header]
+       else [MediaType.toContentType MTApplicationJSON]

 instance JSON.ToJSON PgError where
  toJSON (PgError _ usageError) = JSON.toJSON usageError

 instance JSON.ToJSON SQL.UsageError where
-  toJSON (SQL.ConnectionError e) = JSON.object [
-    "code"    .= ("" :: Text),
+  toJSON (SQL.ConnectionUsageError e) = JSON.object [
+    "code"    .= ConnectionErrorCode00,
    "message" .= ("Database connection error. Retrying the connection." :: Text),
-    "details" .= (T.decodeUtf8With T.lenientDecode $ fromMaybe "" e :: Text)]
-  toJSON (SQL.SessionError e) = JSON.toJSON e -- SQL.Error
+    "details" .= (T.decodeUtf8With T.lenientDecode $ fromMaybe "" e :: Text),
+    "hint"    .= JSON.Null]
+  toJSON (SQL.SessionUsageError e) = JSON.toJSON e -- SQL.Error
+  toJSON SQL.AcquisitionTimeoutUsageError = JSON.object [
+    "code"    .= ConnectionErrorCode00,
+    "message" .= ("Timed out acquiring connection from connection pool." :: Text),
+    "details" .= JSON.Null,
+    "hint"    .= JSON.Null]

 instance JSON.ToJSON SQL.QueryError where
  toJSON (SQL.QueryError _ _ e) = JSON.toJSON e

 instance JSON.ToJSON SQL.CommandError where
-  toJSON (SQL.ResultError (SQL.ServerError c m d h)) = case BS.unpack c of
-    'P':'T':_ -> JSON.object [
-        "details" .= fmap T.decodeUtf8 d,
-        "hint"    .= fmap T.decodeUtf8 h]
+  toJSON (SQL.ResultError (SQL.ServerError c m d h _p)) = JSON.object [
+    "code"     .= (T.decodeUtf8 c      :: Text),
+    "message"  .= (T.decodeUtf8 m      :: Text),
+    "details"  .= (fmap T.decodeUtf8 d :: Maybe Text),
+    "hint"     .= (fmap T.decodeUtf8 h :: Maybe Text)]

-    _         -> JSON.object [
-        "code"    .= (T.decodeUtf8 c      :: Text),
-        "message" .= (T.decodeUtf8 m      :: Text),
-        "details" .= (fmap T.decodeUtf8 d :: Maybe Text),
-        "hint"    .= (fmap T.decodeUtf8 h :: Maybe Text)]
+  toJSON (SQL.ResultError resultError) = JSON.object [
+    "code"    .= InternalErrorCode00,
+    "message" .= (show resultError :: Text),
+    "details" .= JSON.Null,
+    "hint"    .= JSON.Null]

-  toJSON (SQL.ResultError (SQL.UnexpectedResult m)) = JSON.object [
-    "message" .= (m :: Text)]
-  toJSON (SQL.ResultError (SQL.RowError i SQL.EndOfInput)) = JSON.object [
-    "message" .= ("Row error: end of input" :: Text),
-    "details" .= ("Attempt to parse more columns than there are in the result" :: Text),
-    "hint"    .= (("Row number " <> show i) :: Text)]
-  toJSON (SQL.ResultError (SQL.RowError i SQL.UnexpectedNull)) = JSON.object [
-    "message" .= ("Row error: unexpected null" :: Text),
-    "details" .= ("Attempt to parse a NULL as some value." :: Text),
-    "hint"    .= (("Row number " <> show i) :: Text)]
-  toJSON (SQL.ResultError (SQL.RowError i (SQL.ValueError d))) = JSON.object [
-    "message" .= ("Row error: Wrong value parser used" :: Text),
-    "details" .= d,
-    "hint"    .= (("Row number " <> show i) :: Text)]
-  toJSON (SQL.ResultError (SQL.UnexpectedAmountOfRows i)) = JSON.object [
-    "message" .= ("Unexpected amount of rows" :: Text),
-    "details" .= i]
  toJSON (SQL.ClientError d) = JSON.object [
+    "code"    .= ConnectionErrorCode01,
    "message" .= ("Database client error. Retrying the connection." :: Text),
-    "details" .= (fmap T.decodeUtf8 d :: Maybe Text)]
+    "details" .= (fmap T.decodeUtf8 d :: Maybe Text),
+    "hint"    .= JSON.Null]
+

 pgErrorStatus :: Bool -> SQL.UsageError -> HTTP.Status
-pgErrorStatus _      (SQL.ConnectionError _)                                      = HTTP.status503
-pgErrorStatus _      (SQL.SessionError (SQL.QueryError _ _ (SQL.ClientError _)))      = HTTP.status503
-pgErrorStatus authed (SQL.SessionError (SQL.QueryError _ _ (SQL.ResultError rError))) =
+pgErrorStatus _      (SQL.ConnectionUsageError _) = HTTP.status503
+pgErrorStatus _      SQL.AcquisitionTimeoutUsageError = HTTP.status504
+pgErrorStatus _      (SQL.SessionUsageError (SQL.QueryError _ _ (SQL.ClientError _)))      = HTTP.status503
+pgErrorStatus authed (SQL.SessionUsageError (SQL.QueryError _ _ (SQL.ResultError rError))) =
  case rError of
-    (SQL.ServerError c m _ _) ->
+    (SQL.ServerError c m _ _ _) ->
      case BS.unpack c of
        '0':'8':_ -> HTTP.status503 -- pg connection err
        '0':'9':_ -> HTTP.status500 -- triggered action exception
@@ -243,7 +414,9 @@ pgErrorStatus authed (SQL.SessionError (SQL.QueryError _ _ (SQL.ResultError rErr
        "P0001"   -> HTTP.status400 -- default code for "raise"
        'P':'0':_ -> HTTP.status500 -- PL/pgSQL Error
        'X':'X':_ -> HTTP.status500 -- internal Error
-        "42883"   -> HTTP.status404 -- undefined function
+        "42883"-> if BS.isPrefixOf "function xmlagg(" m
+          then HTTP.status406
+          else HTTP.status404 -- undefined function
        "42P01"   -> HTTP.status404 -- undefined table
        "42501"   -> if authed then HTTP.status403 else HTTP.status401 -- insufficient privilege
        'P':'T':n -> fromMaybe HTTP.status500 (HTTP.mkStatus <$> readMaybe n <*> pure m)
@@ -251,89 +424,116 @@ pgErrorStatus authed (SQL.SessionError (SQL.QueryError _ _ (SQL.ResultError rErr

    _                       -> HTTP.status500

-checkIsFatal :: PgError -> Maybe Text
-checkIsFatal (PgError _ (SQL.ConnectionError e))
+checkIsFatal :: SQL.UsageError -> Maybe Text
+checkIsFatal (SQL.ConnectionUsageError e)
  | isAuthFailureMessage = Just $ toS failureMessage
  | otherwise = Nothing
-  where isAuthFailureMessage = "FATAL:  password authentication failed" `isPrefixOf` failureMessage
+  where isAuthFailureMessage = "FATAL:  password authentication failed" `isInfixOf` failureMessage
        failureMessage = BS.unpack $ fromMaybe mempty e
-checkIsFatal (PgError _ (SQL.SessionError (SQL.QueryError _ _ (SQL.ResultError serverError))))
+checkIsFatal(SQL.SessionUsageError (SQL.QueryError _ _ (SQL.ResultError serverError)))
  = case serverError of
      -- Check for a syntax error (42601 is the pg code). This would mean the error is on our part somehow, so we treat it as fatal.
-      SQL.ServerError "42601" _ _ _
+      SQL.ServerError "42601" _ _ _ _
        -> Just "Hint: This is probably a bug in PostgREST, please report it at https://github.com/PostgREST/postgrest/issues"
      -- Check for a "prepared statement <name> already exists" error (Code 42P05: duplicate_prepared_statement).
      -- This would mean that a connection pooler in transaction mode is being used
      -- while prepared statements are enabled in the PostgREST configuration,
      -- both of which are incompatible with each other.
-      SQL.ServerError "42P05" _ _ _
+      SQL.ServerError "42P05" _ _ _ _
        -> Just "Hint: If you are using connection poolers in transaction mode, try setting db-prepared-statements to false."
      -- Check for a "transaction blocks not allowed in statement pooling mode" error (Code 08P01: protocol_violation).
      -- This would mean that a connection pooler in statement mode is being used which is not supported in PostgREST.
-      SQL.ServerError "08P01" "transaction blocks not allowed in statement pooling mode" _ _
+      SQL.ServerError "08P01" "transaction blocks not allowed in statement pooling mode" _ _ _
        -> Just "Hint: Connection poolers in statement mode are not supported."
      _ -> Nothing
 checkIsFatal _ = Nothing


 data Error
-  = GucHeadersError
+  = ApiRequestError ApiRequestError
+  | GucHeadersError
  | GucStatusError
-  | BinaryFieldError ContentType
-  | ConnectionLostError
-  | PutMatchingPkError
-  | PutRangeNotAllowedError
-  | JwtTokenMissing
  | JwtTokenInvalid Text
-  | SingularityError Integer
-  | NotFound
-  | ApiRequestError ApiRequestError
+  | JwtTokenMissing
+  | JwtTokenRequired
+  | NoSchemaCacheError
+  | OffLimitsChangesError Int64 Integer
  | PgErr PgError
+  | PutMatchingPkError
+  | SingularityError Integer

 instance PgrstError Error where
+  status (ApiRequestError err)   = status err
  status GucHeadersError         = HTTP.status500
  status GucStatusError          = HTTP.status500
-  status (BinaryFieldError _)    = HTTP.status406
-  status ConnectionLostError     = HTTP.status503
-  status PutMatchingPkError      = HTTP.status400
-  status PutRangeNotAllowedError = HTTP.status400
+  status JwtTokenInvalid{}       = HTTP.unauthorized401
  status JwtTokenMissing         = HTTP.status500
-  status (JwtTokenInvalid _)     = HTTP.unauthorized401
-  status (SingularityError _)    = HTTP.status406
-  status NotFound                = HTTP.status404
+  status JwtTokenRequired        = HTTP.unauthorized401
+  status NoSchemaCacheError      = HTTP.status503
+  status OffLimitsChangesError{} = HTTP.status400
  status (PgErr err)             = status err
-  status (ApiRequestError err)   = status err
+  status PutMatchingPkError      = HTTP.status400
+  status SingularityError{}      = HTTP.status406

-  headers (SingularityError _)     = [ContentType.toHeader CTSingularJSON]
-  headers (JwtTokenInvalid m)      = [ContentType.toHeader CTApplicationJSON, invalidTokenHeader m]
-  headers (PgErr err)              = headers err
-  headers (ApiRequestError err)    = headers err
-  headers _                        = [ContentType.toHeader CTApplicationJSON]
+  headers (ApiRequestError err)  = headers err
+  headers (JwtTokenInvalid m)    = [MediaType.toContentType MTApplicationJSON, invalidTokenHeader m]
+  headers JwtTokenRequired       = [MediaType.toContentType MTApplicationJSON, requiredTokenHeader]
+  headers (PgErr err)            = headers err
+  headers SingularityError{}     = [MediaType.toContentType MTSingularJSON]
+  headers _                      = [MediaType.toContentType MTApplicationJSON]

 instance JSON.ToJSON Error where
-  toJSON GucHeadersError           = JSON.object [
-    "message" .= ("response.headers guc must be a JSON array composed of objects with a single key and a string value" :: Text)]
-  toJSON GucStatusError           = JSON.object [
-    "message" .= ("response.status guc must be a valid status code" :: Text)]
-  toJSON (BinaryFieldError ct)          = JSON.object [
-    "message" .= ((T.decodeUtf8 (ContentType.toMime ct) <> " requested but more than one column was selected") :: Text)]
-  toJSON ConnectionLostError       = JSON.object [
-    "message" .= ("Database connection lost. Retrying the connection." :: Text)]
+  toJSON NoSchemaCacheError = JSON.object [
+      "code"    .= ConnectionErrorCode02,
+      "message" .= ("Could not query the database for the schema cache. Retrying." :: Text),
+      "details" .= JSON.Null,
+      "hint"    .= JSON.Null]

-  toJSON PutRangeNotAllowedError   = JSON.object [
-    "message" .= ("Range header and limit/offset querystring parameters are not allowed for PUT" :: Text)]
-  toJSON PutMatchingPkError        = JSON.object [
-    "message" .= ("Payload values do not match URL in primary key column(s)" :: Text)]
-
-  toJSON (SingularityError n)      = JSON.object [
-    "message" .= ("JSON object requested, multiple (or no) rows returned" :: Text),
-    "details" .= T.unwords ["Results contain", show n, "rows,", T.decodeUtf8 (ContentType.toMime CTSingularJSON), "requires 1 row"]]
-
-  toJSON JwtTokenMissing           = JSON.object [
-    "message" .= ("Server lacks JWT secret" :: Text)]
+  toJSON JwtTokenMissing = JSON.object [
+      "code"    .= JWTErrorCode00,
+      "message" .= ("Server lacks JWT secret" :: Text),
+      "details" .= JSON.Null,
+      "hint"    .= JSON.Null]
  toJSON (JwtTokenInvalid message) = JSON.object [
-    "message" .= (message :: Text)]
-  toJSON NotFound = JSON.object []
+      "code"    .= JWTErrorCode01,
+      "message" .= (message :: Text),
+      "details" .= JSON.Null,
+      "hint"    .= JSON.Null]
+  toJSON JwtTokenRequired = JSON.object [
+      "code"    .= JWTErrorCode02,
+      "message" .= ("Anonymous access is disabled" :: Text),
+      "details" .= JSON.Null,
+      "hint"    .= JSON.Null]
+
+  toJSON (OffLimitsChangesError n maxs) = JSON.object [
+      "code"    .= ApiRequestErrorCode10,
+      "message" .= ("The maximum number of rows allowed to change was surpassed" :: Text),
+      "details" .= T.unwords ["Results contain", show n, "rows changed but the maximum number allowed is", show maxs],
+      "hint"    .= JSON.Null]
+
+  toJSON GucHeadersError = JSON.object [
+    "code"    .= ApiRequestErrorCode11,
+    "message" .= ("response.headers guc must be a JSON array composed of objects with a single key and a string value" :: Text),
+    "details" .= JSON.Null,
+    "hint"    .= JSON.Null]
+  toJSON GucStatusError = JSON.object [
+    "code"    .= ApiRequestErrorCode12,
+    "message" .= ("response.status guc must be a valid status code" :: Text),
+    "details" .= JSON.Null,
+    "hint"    .= JSON.Null]
+
+  toJSON PutMatchingPkError = JSON.object [
+    "code"    .= ApiRequestErrorCode15,
+    "message" .= ("Payload values do not match URL in primary key column(s)" :: Text),
+    "details" .= JSON.Null,
+    "hint"    .= JSON.Null]
+
+  toJSON (SingularityError n) = JSON.object [
+    "code"    .= ApiRequestErrorCode16,
+    "message" .= ("JSON object requested, multiple (or no) rows returned" :: Text),
+    "details" .= T.unwords ["Results contain", show n, "rows,", T.decodeUtf8 (MediaType.toMime MTSingularJSON), "requires 1 row"],
+    "hint"    .= JSON.Null]
+
  toJSON (PgErr err) = JSON.toJSON err
  toJSON (ApiRequestError err) = JSON.toJSON err

@@ -341,5 +541,86 @@ invalidTokenHeader :: Text -> Header
 invalidTokenHeader m =
  ("WWW-Authenticate", "Bearer error=\"invalid_token\", " <> "error_description=" <> encodeUtf8 (show m))

+requiredTokenHeader :: Header
+requiredTokenHeader = ("WWW-Authenticate", "Bearer")
+
 singularityError :: (Integral a) => a -> Error
 singularityError = SingularityError . toInteger
+
+-- Error codes are grouped by common modules or characteristics
+data ErrorCode
+  -- PostgreSQL connection errors
+  = ConnectionErrorCode00
+  | ConnectionErrorCode01
+  | ConnectionErrorCode02
+  -- API Request errors
+  | ApiRequestErrorCode00
+  | ApiRequestErrorCode01
+  | ApiRequestErrorCode02
+  | ApiRequestErrorCode03
+  | ApiRequestErrorCode04
+  | ApiRequestErrorCode05
+  | ApiRequestErrorCode06
+  | ApiRequestErrorCode07
+  | ApiRequestErrorCode08
+  | ApiRequestErrorCode09
+  | ApiRequestErrorCode10
+  | ApiRequestErrorCode11
+  | ApiRequestErrorCode12
+  | ApiRequestErrorCode13
+  | ApiRequestErrorCode14
+  | ApiRequestErrorCode15
+  | ApiRequestErrorCode16
+  | ApiRequestErrorCode17
+  -- Schema Cache errors
+  | SchemaCacheErrorCode00
+  | SchemaCacheErrorCode01
+  | SchemaCacheErrorCode02
+  | SchemaCacheErrorCode03
+  -- JWT authentication errors
+  | JWTErrorCode00
+  | JWTErrorCode01
+  | JWTErrorCode02
+  -- Internal errors related to the Hasql library
+  | InternalErrorCode00
+
+instance JSON.ToJSON ErrorCode where
+  toJSON e = JSON.toJSON (buildErrorCode e)
+
+-- New group of errors will be added at the end of all the groups and will have the next prefix in the sequence
+-- New errors are added at the end of the group they belong to and will have the next code in the sequence
+buildErrorCode :: ErrorCode -> Text
+buildErrorCode code = "PGRST" <> case code of
+  ConnectionErrorCode00  -> "000"
+  ConnectionErrorCode01  -> "001"
+  ConnectionErrorCode02  -> "002"
+
+  ApiRequestErrorCode00  -> "100"
+  ApiRequestErrorCode01  -> "101"
+  ApiRequestErrorCode02  -> "102"
+  ApiRequestErrorCode03  -> "103"
+  ApiRequestErrorCode04  -> "104"
+  ApiRequestErrorCode05  -> "105"
+  ApiRequestErrorCode06  -> "106"
+  ApiRequestErrorCode07  -> "107"
+  ApiRequestErrorCode08  -> "108"
+  ApiRequestErrorCode09  -> "109"
+  ApiRequestErrorCode10  -> "110"
+  ApiRequestErrorCode11  -> "111"
+  ApiRequestErrorCode12  -> "112"
+  ApiRequestErrorCode13  -> "113"
+  ApiRequestErrorCode14  -> "114"
+  ApiRequestErrorCode15  -> "115"
+  ApiRequestErrorCode16  -> "116"
+  ApiRequestErrorCode17  -> "117"
+
+  SchemaCacheErrorCode00 -> "200"
+  SchemaCacheErrorCode01 -> "201"
+  SchemaCacheErrorCode02 -> "202"
+  SchemaCacheErrorCode03 -> "203"
+
+  JWTErrorCode00         -> "300"
+  JWTErrorCode01         -> "301"
+  JWTErrorCode02         -> "302"
+
+  InternalErrorCode00    -> "X00"
@@ -0,0 +1,30 @@
+{-|
+Module      : PostgREST.Logger
+Description : Wai Middleware to log requests to stdout.
+-}
+module PostgREST.Logger (middleware) where
+
+import qualified Network.Wai                          as Wai
+import qualified Network.Wai.Middleware.RequestLogger as Wai
+
+import Network.HTTP.Types.Status (status400, status500)
+import System.IO.Unsafe          (unsafePerformIO)
+
+import qualified PostgREST.Auth   as Auth
+import           PostgREST.Config (LogLevel (..))
+
+import Protolude
+
+middleware :: LogLevel -> Wai.Middleware
+middleware logLevel = case logLevel of
+  LogInfo  -> requestLogger (const True)
+  LogWarn  -> requestLogger (>= status400)
+  LogError -> requestLogger (>= status500)
+  LogCrit  -> requestLogger (const False)
+  where
+    requestLogger filterStatus = unsafePerformIO $ Wai.mkRequestLogger Wai.defaultRequestLoggerSettings
+      { Wai.outputFormat = Wai.ApacheWithSettings $
+          Wai.defaultApacheSettings
+            & Wai.setApacheRequestFilter (\_ res -> filterStatus $ Wai.responseStatus res)
+            & Wai.setApacheUserGetter (fmap encodeUtf8 . Auth.getRole)
+      }
@@ -0,0 +1,124 @@
+{-# LANGUAGE DuplicateRecordFields #-}
+
+module PostgREST.MediaType
+  ( MediaType(..)
+  , MTPlanOption (..)
+  , MTPlanFormat (..)
+  , MTPlanAttrs(..)
+  , toContentType
+  , toMime
+  , decodeMediaType
+  , getMediaType
+  ) where
+
+import qualified Data.ByteString          as BS
+import qualified Data.ByteString.Internal as BS (c2w)
+import           Data.Maybe               (fromJust)
+
+import Network.HTTP.Types.Header (Header, hContentType)
+
+import Protolude
+
+-- | Enumeration of currently supported media types
+data MediaType
+  = MTApplicationJSON
+  | MTSingularJSON
+  | MTGeoJSON
+  | MTTextCSV
+  | MTTextPlain
+  | MTTextXML
+  | MTOpenAPI
+  | MTUrlEncoded
+  | MTOctetStream
+  | MTAny
+  | MTOther ByteString
+  | MTPlan MTPlanAttrs
+  deriving Eq
+
+data MTPlanAttrs = MTPlanAttrs (Maybe MediaType) MTPlanFormat [MTPlanOption]
+instance Eq MTPlanAttrs where
+  MTPlanAttrs {} == MTPlanAttrs {} = True -- we don't care about the attributes when comparing two MTPlan media types
+
+data MTPlanOption
+  = PlanAnalyze | PlanVerbose | PlanSettings | PlanBuffers | PlanWAL
+
+data MTPlanFormat
+  = PlanJSON | PlanText
+
+-- | Convert MediaType to a Content-Type HTTP Header
+toContentType :: MediaType -> Header
+toContentType ct = (hContentType, toMime ct <> charset)
+  where
+    charset = case ct of
+      MTOctetStream -> mempty
+      MTOther _     -> mempty
+      _             -> "; charset=utf-8"
+
+-- | Convert from MediaType to a ByteString representing the mime type
+toMime :: MediaType -> ByteString
+toMime MTApplicationJSON = "application/json"
+toMime MTGeoJSON         = "application/geo+json"
+toMime MTTextCSV         = "text/csv"
+toMime MTTextPlain       = "text/plain"
+toMime MTTextXML         = "text/xml"
+toMime MTOpenAPI         = "application/openapi+json"
+toMime MTSingularJSON    = "application/vnd.pgrst.object+json"
+toMime MTUrlEncoded      = "application/x-www-form-urlencoded"
+toMime MTOctetStream     = "application/octet-stream"
+toMime MTAny             = "*/*"
+toMime (MTOther ct)      = ct
+toMime (MTPlan (MTPlanAttrs mt fmt opts)) =
+  "application/vnd.pgrst.plan+" <> toMimePlanFormat fmt <>
+  (if isNothing mt then mempty else "; for=\"" <> toMime (fromJust mt) <> "\"") <>
+  (if null opts then mempty else "; options=" <> BS.intercalate "|" (toMimePlanOption <$> opts))
+
+toMimePlanOption :: MTPlanOption -> ByteString
+toMimePlanOption PlanAnalyze  = "analyze"
+toMimePlanOption PlanVerbose  = "verbose"
+toMimePlanOption PlanSettings = "settings"
+toMimePlanOption PlanBuffers  = "buffers"
+toMimePlanOption PlanWAL      = "wal"
+
+toMimePlanFormat :: MTPlanFormat -> ByteString
+toMimePlanFormat PlanJSON = "json"
+toMimePlanFormat PlanText = "text"
+
+-- | Convert from ByteString to MediaType. Warning: discards MIME parameters
+decodeMediaType :: BS.ByteString -> MediaType
+decodeMediaType mt =
+  case BS.split (BS.c2w ';') mt of
+    "application/json":_                   -> MTApplicationJSON
+    "application/geo+json":_               -> MTGeoJSON
+    "text/csv":_                           -> MTTextCSV
+    "text/plain":_                         -> MTTextPlain
+    "text/xml":_                           -> MTTextXML
+    "application/openapi+json":_           -> MTOpenAPI
+    "application/vnd.pgrst.object+json":_  -> MTSingularJSON
+    "application/vnd.pgrst.object":_       -> MTSingularJSON
+    "application/x-www-form-urlencoded":_  -> MTUrlEncoded
+    "application/octet-stream":_           -> MTOctetStream
+    "application/vnd.pgrst.plan":rest      -> getPlan PlanText rest
+    "application/vnd.pgrst.plan+text":rest -> getPlan PlanText rest
+    "application/vnd.pgrst.plan+json":rest -> getPlan PlanJSON rest
+    "*/*":_                                -> MTAny
+    other:_                                -> MTOther other
+    _                                      -> MTAny
+  where
+    getPlan fmt rest =
+     let
+       opts         = BS.split (BS.c2w '|') $ fromMaybe mempty (BS.stripPrefix "options=" =<< find (BS.isPrefixOf "options=") rest)
+       inOpts str   = str `elem` opts
+       mtFor        = decodeMediaType . dropAround (== BS.c2w '"') <$> (BS.stripPrefix "for=" =<< find (BS.isPrefixOf "for=") rest)
+       dropAround p = BS.dropWhile p . BS.dropWhileEnd p in
+     MTPlan $ MTPlanAttrs mtFor fmt $
+      [PlanAnalyze  | inOpts "analyze" ] ++
+      [PlanVerbose  | inOpts "verbose" ] ++
+      [PlanSettings | inOpts "settings"] ++
+      [PlanBuffers  | inOpts "buffers" ] ++
+      [PlanWAL      | inOpts "wal"     ]
+
+getMediaType :: MediaType -> MediaType
+getMediaType mt = case mt of
+  MTPlan (MTPlanAttrs (Just mType) _ _) -> mType
+  MTPlan (MTPlanAttrs Nothing _ _)      -> MTApplicationJSON
+  other                                 -> other
@@ -1,204 +0,0 @@
-{-|
-Module      : PostgREST.Middleware
-Description : Sets CORS policy. Also the PostgreSQL GUCs, role, search_path and pre-request function.
-}
-{-# LANGUAGE RecordWildCards #-}
-module PostgREST.Middleware
-  ( runPgLocals
-  , pgrstFormat
-  , pgrstMiddleware
-  , defaultCorsPolicy
-  , corsPolicy
-  , optionalRollback
-  ) where
-
-import qualified Data.Aeson                           as JSON
-import qualified Data.ByteString.Char8                as BS
-import qualified Data.ByteString.Lazy.Char8           as LBS
-import qualified Data.CaseInsensitive                 as CI
-import qualified Data.HashMap.Strict                  as M
-import qualified Data.Text                            as T
-import qualified Data.Text.Encoding                   as T
-import qualified Hasql.Decoders                       as HD
-import qualified Hasql.DynamicStatements.Snippet      as SQL hiding
-                                                             (sql)
-import qualified Hasql.DynamicStatements.Statement    as SQL
-import qualified Hasql.Transaction                    as SQL
-import qualified Network.Wai                          as Wai
-import qualified Network.Wai.Logger                   as Wai
-import qualified Network.Wai.Middleware.Cors          as Wai
-import qualified Network.Wai.Middleware.Gzip          as Wai
-import qualified Network.Wai.Middleware.RequestLogger as Wai
-import qualified Network.Wai.Middleware.Static        as Wai
-
-import Control.Arrow ((***))
-
-import Data.Function             (id)
-import Data.List                 (lookup)
-import Data.Scientific           (FPFormat (..), formatScientific,
-                                  isInteger)
-import Network.HTTP.Types.Status (Status, status400, status500,
-                                  statusCode)
-import System.IO.Unsafe          (unsafePerformIO)
-import System.Log.FastLogger     (toLogStr)
-
-import PostgREST.Config             (AppConfig (..), LogLevel (..))
-import PostgREST.Config.PgVersion   (PgVersion (..), pgVersion140)
-import PostgREST.Error              (Error, errorResponseFor)
-import PostgREST.GucHeader          (addHeadersIfNotIncluded)
-import PostgREST.Query.SqlFragment  (fromQi, intercalateSnippet,
-                                     unknownEncoder)
-import PostgREST.Request.ApiRequest (ApiRequest (..), Target (..))
-
-import PostgREST.Request.Preferences
-
-import Protolude
-
-- | Runs local(transaction scoped) GUCs for every request, plus the pre-request function
-runPgLocals :: AppConfig   -> M.HashMap Text JSON.Value ->
-               (ApiRequest -> ExceptT Error SQL.Transaction Wai.Response) ->
-               ApiRequest  -> ByteString -> PgVersion -> ExceptT Error SQL.Transaction Wai.Response
-runPgLocals conf claims app req jsonDbS actualPgVersion = do
-  lift $ SQL.statement mempty $ SQL.dynamicallyParameterized
-    ("select " <> intercalateSnippet ", " (searchPathSql : roleSql ++ claimsSql ++ [methodSql, pathSql] ++ headersSql ++ cookiesSql ++ appSettingsSql ++ specSql))
-    HD.noResult (configDbPreparedStatements conf)
-  lift $ traverse_ SQL.sql preReqSql
-  app req
-  where
-    methodSql = setConfigLocal mempty ("request.method", iMethod req)
-    pathSql = setConfigLocal mempty ("request.path", iPath req)
-    headersSql = if usesLegacyGucs
-                   then setConfigLocal "request.header." <$> iHeaders req
-                   else setConfigLocalJson "request.headers" (iHeaders req)
-    cookiesSql = if usesLegacyGucs
-                   then setConfigLocal "request.cookie." <$> iCookies req
-                   else setConfigLocalJson "request.cookies" (iCookies req)
-    claimsWithRole =
-      let anon = JSON.String . toS $ configDbAnonRole conf in -- role claim defaults to anon if not specified in jwt
-      M.union claims (M.singleton "role" anon)
-    claimsSql = if usesLegacyGucs
-                  then setConfigLocal "request.jwt.claim." <$> [(toUtf8 c, toUtf8 $ unquoted v) | (c,v) <- M.toList claimsWithRole]
-                  else [setConfigLocal mempty ("request.jwt.claims", LBS.toStrict $ JSON.encode claimsWithRole)]
-    roleSql = maybeToList $ (\x -> setConfigLocal mempty ("role", toUtf8 $ unquoted x)) <$> M.lookup "role" claimsWithRole
-    appSettingsSql = setConfigLocal mempty <$> (join bimap toUtf8 <$> configAppSettings conf)
-    searchPathSql =
-      let schemas = T.intercalate ", " (iSchema req : configDbExtraSearchPath conf) in
-      setConfigLocal mempty ("search_path", toUtf8 schemas)
-    preReqSql = (\f -> "select " <> fromQi f <> "();") <$> configDbPreRequest conf
-    specSql = case iTarget req of
-      TargetProc{tpIsRootSpec=True} -> [setConfigLocal mempty ("request.spec", jsonDbS)]
-      _                             -> mempty
-    usesLegacyGucs = configDbUseLegacyGucs conf && actualPgVersion < pgVersion140
-
-- | Log in apache format. Only requests that have a status greater than minStatus are logged.
-- | There's no way to filter logs in the apache format on wai-extra: https://hackage.haskell.org/package/wai-extra-3.0.29.2/docs/Network-Wai-Middleware-RequestLogger.html#t:OutputFormat.
-- | So here we copy wai-logger apacheLogStr function: https://github.com/kazu-yamamoto/logger/blob/a4f51b909a099c51af7a3f75cf16e19a06f9e257/wai-logger/Network/Wai/Logger/Apache.hs#L45
-- | TODO: Add the ability to filter apache logs on wai-extra and remove this function.
-pgrstFormat :: Status -> Wai.OutputFormatter
-pgrstFormat minStatus date req status responseSize =
-  if status < minStatus
-    then mempty
-  else toLogStr (getSourceFromSocket req)
-    <> " - - ["
-    <> toLogStr date
-    <> "] \""
-    <> toLogStr (Wai.requestMethod req)
-    <> " "
-    <> toLogStr (Wai.rawPathInfo req <> Wai.rawQueryString req)
-    <> " "
-    <> toLogStr (show (Wai.httpVersion req)::Text)
-    <> "\" "
-    <> toLogStr (show (statusCode status)::Text)
-    <> " "
-    <> toLogStr (maybe "-" show responseSize::Text)
-    <> " \""
-    <> toLogStr (fromMaybe mempty $ Wai.requestHeaderReferer req)
-    <> "\" \""
-    <> toLogStr (fromMaybe mempty $ Wai.requestHeaderUserAgent req)
-    <> "\"\n"
-  where
-    getSourceFromSocket = BS.pack . Wai.showSockAddr . Wai.remoteHost
-
-pgrstMiddleware :: LogLevel -> Wai.Application -> Wai.Application
-pgrstMiddleware logLevel =
-    logger
-  . Wai.cors corsPolicy
-  . Wai.staticPolicy (Wai.only [("favicon.ico", "static/favicon.ico")])
-  where
-    logger = case logLevel of
-      LogCrit  -> id
-      LogError -> unsafePerformIO $ Wai.mkRequestLogger Wai.def { Wai.outputFormat = Wai.CustomOutputFormat $ pgrstFormat status500}
-      LogWarn  -> unsafePerformIO $ Wai.mkRequestLogger Wai.def { Wai.outputFormat = Wai.CustomOutputFormat $ pgrstFormat status400}
-      LogInfo  -> Wai.logStdout
-
-defaultCorsPolicy :: Wai.CorsResourcePolicy
-defaultCorsPolicy =  Wai.CorsResourcePolicy Nothing
-  ["GET", "POST", "PATCH", "PUT", "DELETE", "OPTIONS"] ["Authorization"] Nothing
-  (Just $ 60*60*24) False False True
-
-- | CORS policy to be used in by Wai Cors middleware
-corsPolicy :: Wai.Request -> Maybe Wai.CorsResourcePolicy
-corsPolicy req = case lookup "origin" headers of
-  Just origin -> Just defaultCorsPolicy {
-      Wai.corsOrigins = Just ([origin], True)
-    , Wai.corsRequestHeaders = "Authentication" : accHeaders
-    , Wai.corsExposedHeaders = Just [
-        "Content-Encoding", "Content-Location", "Content-Range", "Content-Type"
-      , "Date", "Location", "Server", "Transfer-Encoding", "Range-Unit"
-      ]
-    }
-  Nothing -> Nothing
-  where
-    headers = Wai.requestHeaders req
-    accHeaders = case lookup "access-control-request-headers" headers of
-      Just hdrs -> map (CI.mk . BS.strip) $ BS.split ',' hdrs
-      Nothing   -> []
-
-unquoted :: JSON.Value -> Text
-unquoted (JSON.String t) = t
-unquoted (JSON.Number n) =
-  toS $ formatScientific Fixed (if isInteger n then Just 0 else Nothing) n
-unquoted (JSON.Bool b) = show b
-unquoted v = T.decodeUtf8 . LBS.toStrict $ JSON.encode v
-
-- | Set a transaction to eventually roll back if requested and set respective
-- headers on the response.
-optionalRollback
-  :: AppConfig
-  -> ApiRequest
-  -> ExceptT Error SQL.Transaction Wai.Response
-  -> ExceptT Error SQL.Transaction Wai.Response
-optionalRollback AppConfig{..} ApiRequest{..} transaction = do
-  resp <- catchError transaction $ return . errorResponseFor
-  when (shouldRollback || (configDbTxRollbackAll && not shouldCommit))
-    (lift SQL.condemn)
-  return $ Wai.mapResponseHeaders preferenceApplied resp
-  where
-    shouldCommit =
-      configDbTxAllowOverride && iPreferTransaction == Just Commit
-    shouldRollback =
-      configDbTxAllowOverride && iPreferTransaction == Just Rollback
-    preferenceApplied
-      | shouldCommit =
-          addHeadersIfNotIncluded
-            [toAppliedHeader Commit]
-      | shouldRollback =
-          addHeadersIfNotIncluded
-            [toAppliedHeader Rollback]
-      | otherwise =
-          identity
-
-- | Do a pg set_config(setting, value, true) call. This is equivalent to a SET LOCAL.
-setConfigLocal :: ByteString -> (ByteString, ByteString) -> SQL.Snippet
-setConfigLocal prefix (k, v) =
-  "set_config(" <> unknownEncoder (prefix <> k) <> ", " <> unknownEncoder v <> ", true)"
-
-- | Starting from PostgreSQL v14, some characters are not allowed for config names (mostly affecting headers with "-").
-- | A JSON format string is used to avoid this problem. See https://github.com/PostgREST/postgrest/issues/1857
-setConfigLocalJson :: ByteString -> [(ByteString, ByteString)] -> [SQL.Snippet]
-setConfigLocalJson prefix keyVals = [setConfigLocal mempty (prefix, gucJsonVal keyVals)]
-  where
-    gucJsonVal :: [(ByteString, ByteString)] -> ByteString
-    gucJsonVal = LBS.toStrict . JSON.encode . M.fromList . arrayByteStringToText
-    arrayByteStringToText :: [(ByteString, ByteString)] -> [(Text,Text)]
-    arrayByteStringToText keyVal = (T.decodeUtf8 *** T.decodeUtf8) <$> keyVal
@@ -0,0 +1,433 @@
+{-|
+Module      : PostgREST.Plan
+Description : PostgREST Request Planner
+
+This module is in charge of building an intermediate
+representation between the HTTP request and the
+final resulting SQL query.
+
+A query tree is built in case of resource embedding. By inferring the
+relationship between tables, join conditions are added for every embedded
+resource.
+-}
+{-# LANGUAGE DuplicateRecordFields #-}
+{-# LANGUAGE LambdaCase            #-}
+{-# LANGUAGE NamedFieldPuns        #-}
+{-# LANGUAGE RecordWildCards       #-}
+
+module PostgREST.Plan
+  ( readPlan
+  , mutateReadPlan
+  , callReadPlan
+  , MutateReadPlan(..)
+  , CallReadPlan(..)
+  ) where
+
+import qualified Data.HashMap.Strict        as HM
+import qualified Data.Set                   as S
+import qualified PostgREST.SchemaCache.Proc as Proc
+
+import Data.Either.Combinators (mapLeft)
+import Data.List               (delete)
+import Data.Tree               (Tree (..))
+
+import PostgREST.ApiRequest               (Action (..),
+                                           ApiRequest (..),
+                                           InvokeMethod (..),
+                                           Mutation (..),
+                                           Payload (..))
+import PostgREST.Config                   (AppConfig (..))
+import PostgREST.Error                    (Error (..))
+import PostgREST.Query.SqlFragment        (sourceCTEName)
+import PostgREST.RangeQuery               (NonnegRange, allRange,
+                                           convertToLimitZeroRange,
+                                           restrictRange)
+import PostgREST.SchemaCache              (SchemaCache (..))
+import PostgREST.SchemaCache.Identifiers  (FieldName,
+                                           QualifiedIdentifier (..),
+                                           Schema)
+import PostgREST.SchemaCache.Proc         (ProcDescription (..),
+                                           ProcParam (..),
+                                           procReturnsScalar)
+import PostgREST.SchemaCache.Relationship (Cardinality (..),
+                                           Junction (..),
+                                           Relationship (..),
+                                           RelationshipsMap)
+import PostgREST.SchemaCache.Table        (tablePKCols)
+
+import PostgREST.Plan.CallPlan
+import PostgREST.Plan.MutatePlan
+import PostgREST.Plan.ReadPlan   as ReadPlan
+
+import PostgREST.ApiRequest.Preferences
+import PostgREST.ApiRequest.Types
+
+import qualified PostgREST.ApiRequest.QueryParams as QueryParams
+
+import Protolude hiding (from)
+
+data MutateReadPlan = MutateReadPlan {
+  mrReadPlan   :: ReadPlanTree
+, mrMutatePlan :: MutatePlan
+}
+
+data CallReadPlan = CallReadPlan {
+  crReadPlan :: ReadPlanTree
+, crCallPlan :: CallPlan
+}
+
+mutateReadPlan :: Mutation -> ApiRequest -> QualifiedIdentifier -> AppConfig -> SchemaCache -> Either Error MutateReadPlan
+mutateReadPlan  mutation apiRequest identifier conf sCache = do
+  rPlan <- readPlan identifier conf sCache apiRequest
+  mPlan <- mutatePlan mutation identifier apiRequest sCache rPlan
+  return $ MutateReadPlan rPlan mPlan
+
+callReadPlan :: ProcDescription -> AppConfig -> SchemaCache -> ApiRequest -> Either Error CallReadPlan
+callReadPlan proc conf sCache apiRequest = do
+  let identifier = QualifiedIdentifier (pdSchema proc) (fromMaybe (pdName proc) $ Proc.procTableName proc)
+  rPlan <- readPlan identifier conf sCache apiRequest
+  let cPlan = callPlan proc apiRequest rPlan
+  return $ CallReadPlan rPlan cPlan
+
+-- | Builds the ReadPlan tree on a number of stages.
+-- | Adds filters, order, limits on its respective nodes.
+-- | Adds joins conditions obtained from resource embedding.
+readPlan :: QualifiedIdentifier -> AppConfig -> SchemaCache -> ApiRequest -> Either Error ReadPlanTree
+readPlan qi@QualifiedIdentifier{..} AppConfig{configDbMaxRows} SchemaCache{dbRelationships} apiRequest  =
+  mapLeft ApiRequestError $
+  treeRestrictRange configDbMaxRows (iAction apiRequest) =<<
+  addRels qiSchema (iAction apiRequest) dbRelationships Nothing =<<
+  addLogicTrees apiRequest =<<
+  addRanges apiRequest =<<
+  addOrders apiRequest =<<
+  addFilters apiRequest (initReadRequest qi $ QueryParams.qsSelect $ iQueryParams apiRequest)
+
+-- Build the initial read plan tree
+initReadRequest :: QualifiedIdentifier -> [Tree SelectItem] -> ReadPlanTree
+initReadRequest qi@QualifiedIdentifier{..} =
+  foldr (treeEntry rootDepth) $ Node defReadPlan{from=qi, relName=qiName, depth=rootDepth} []
+  where
+    rootDepth = 0
+    defReadPlan = ReadPlan [] (QualifiedIdentifier mempty mempty) Nothing [] [] allRange mempty Nothing [] Nothing mempty Nothing Nothing rootDepth
+    treeEntry :: Depth -> Tree SelectItem -> ReadPlanTree -> ReadPlanTree
+    treeEntry depth (Node SelectRelation{..} fldForest) (Node q rForest) =
+      let nxtDepth = succ depth in
+        Node q $
+          foldr (treeEntry nxtDepth)
+          (Node defReadPlan{from=QualifiedIdentifier qiSchema selRelation, relName=selRelation, relAlias=selAlias, relHint=selHint, relJoinType=selJoinType, depth=nxtDepth} [])
+          fldForest:rForest
+    treeEntry _ (Node SelectField{..} _) (Node q rForest) = Node q{select=(selField, selCast, selAlias):select q} rForest
+
+-- | Enforces the `max-rows` config on the result
+treeRestrictRange :: Maybe Integer -> Action -> ReadPlanTree -> Either ApiRequestError ReadPlanTree
+treeRestrictRange _ (ActionMutate _) request = Right request
+treeRestrictRange maxRows _ request = pure $ nodeRestrictRange maxRows <$> request
+  where
+    nodeRestrictRange :: Maybe Integer -> ReadPlan -> ReadPlan
+    nodeRestrictRange m q@ReadPlan{range_=r} = q{range_= convertToLimitZeroRange r (restrictRange m r) }
+
+-- add relationships to the nodes of the tree by traversing the forest while keeping track of the parentNode(https://stackoverflow.com/questions/22721064/get-the-parent-of-a-node-in-data-tree-haskell#comment34627048_22721064)
+-- also adds aliasing
+addRels :: Schema -> Action -> RelationshipsMap -> Maybe ReadPlanTree -> ReadPlanTree -> Either ApiRequestError ReadPlanTree
+addRels schema action allRels parentNode (Node rPlan@ReadPlan{relName,relHint,relAlias,depth} forest) =
+  case parentNode of
+    Just (Node ReadPlan{from=parentNodeQi, fromAlias=parentAlias} _) ->
+      let
+        newReadPlan = (\r ->
+          let newAlias = Just (qiName (relForeignTable r) <> "_" <> show depth)
+              aggAlias = qiName (relTable r) <> "_" <> fromMaybe relName relAlias <> "_" <> show depth in
+          case r of
+            Relationship{relCardinality=M2M _} -> -- m2m does internal implicit joins that don't need aliasing
+              rPlan{from=relForeignTable r, relToParent=Just r, relAggAlias=aggAlias, relJoinConds=getJoinConditions Nothing parentAlias r}
+            ComputedRelationship{} ->
+              rPlan{from=relForeignTable r, relToParent=Just r{relTable=maybe (relTable r) (QualifiedIdentifier mempty) parentAlias}, relAggAlias=aggAlias, fromAlias=newAlias}
+            _ ->
+              rPlan{from=relForeignTable r, relToParent=Just r, relAggAlias=aggAlias, fromAlias=newAlias, relJoinConds=getJoinConditions newAlias parentAlias r}
+          ) <$> rel
+        origin = if depth == 1 -- Only on depth 1 we check if the root(depth 0) has an alias so the sourceCTEName alias can be found as a relationship
+          then fromMaybe (qiName parentNodeQi) parentAlias
+          else qiName parentNodeQi
+        rel = findRel schema allRels origin relName relHint
+      in
+      Node <$> newReadPlan <*> (updateForest . hush $ Node <$> newReadPlan <*> pure forest)
+    Nothing -> -- root case
+      let
+        newFrom  = QualifiedIdentifier mempty $ decodeUtf8 sourceCTEName
+        newAlias = Just (qiName $ from rPlan)
+        newReadPlan = case action of
+          -- the CTE for mutations/rpc is used as WITH sourceCTEName .. SELECT .. FROM sourceCTEName as alias,
+          -- we use the table name as an alias so findRel can find the right relationship.
+          ActionMutate _ -> rPlan{from=newFrom, fromAlias=newAlias}
+          ActionInvoke _ -> rPlan{from=newFrom, fromAlias=newAlias}
+          _              -> rPlan
+      in
+      Node newReadPlan <$> updateForest (Just $ Node newReadPlan forest)
+  where
+    updateForest :: Maybe ReadPlanTree -> Either ApiRequestError [ReadPlanTree]
+    updateForest rq = addRels schema action allRels rq `traverse` forest
+
+getJoinConditions :: Maybe Alias -> Maybe Alias -> Relationship -> [JoinCondition]
+getJoinConditions _ _ ComputedRelationship{} = []
+getJoinConditions tblAlias parentAlias Relationship{relTable=qi,relForeignTable=fQi,relCardinality=card} =
+  case card of
+    M2M (Junction QualifiedIdentifier{qiName=jtn} _ _ jcols1 jcols2) ->
+      (toJoinCondition Nothing Nothing ftN jtn <$> jcols2) ++ (toJoinCondition parentAlias tblAlias tN jtn <$> jcols1)
+    O2M _ cols ->
+      toJoinCondition parentAlias tblAlias tN ftN <$> cols
+    M2O _ cols ->
+      toJoinCondition parentAlias tblAlias tN ftN <$> cols
+    O2O _ cols ->
+      toJoinCondition parentAlias tblAlias tN ftN <$> cols
+  where
+    QualifiedIdentifier{qiSchema=tSchema, qiName=tN} = qi
+    QualifiedIdentifier{qiName=ftN} = fQi
+    toJoinCondition :: Maybe Alias -> Maybe Alias -> Text -> Text -> (FieldName, FieldName) -> JoinCondition
+    toJoinCondition prAl newAl tb ftb (c, fc) =
+      let qi1 = QualifiedIdentifier tSchema ftb
+          qi2 = QualifiedIdentifier tSchema tb in
+        JoinCondition (maybe qi1 (QualifiedIdentifier mempty) newAl, fc)
+                      (maybe qi2 (QualifiedIdentifier mempty) prAl, c)
+
+-- Finds a relationship between an origin and a target in the request:
+-- /origin?select=target(*) If more than one relationship is found then the
+-- request is ambiguous and we return an error.  In that case the request can
+-- be disambiguated by adding precision to the target or by using a hint:
+-- /origin?select=target!hint(*). The origin can be a table or view.
+findRel :: Schema -> RelationshipsMap -> NodeName -> NodeName -> Maybe Hint -> Either ApiRequestError Relationship
+findRel schema allRels origin target hint =
+  case rels of
+    []  -> Left $ NoRelBetween origin target hint schema allRels
+    [r] -> Right r
+    rs  -> Left $ AmbiguousRelBetween origin target rs
+  where
+    matchFKSingleCol hint_ card = case card of
+      O2M _ [(col, _)] -> hint_ == col
+      M2O _ [(col, _)] -> hint_ == col
+      O2O _ [(col, _)] -> hint_ == col
+      _                -> False
+    matchFKRefSingleCol hint_ card  = case card of
+      O2M _ [(_, fCol)] -> hint_ == fCol
+      M2O _ [(_, fCol)] -> hint_ == fCol
+      O2O _ [(_, fCol)] -> hint_ == fCol
+      _                 -> False
+    matchConstraint tar card = case card of
+      O2M cons _ -> tar == cons
+      M2O cons _ -> tar == cons
+      O2O cons _ -> tar == cons
+      _          -> False
+    matchJunction hint_ card = case card of
+      M2M Junction{junTable} -> hint_ == qiName junTable
+      _                      -> False
+    isM2O card = case card of
+      M2O _ _ -> True
+      _       -> False
+    isO2M card = case card of
+      O2M _ _ -> True
+      _       -> False
+    rels = filter (\case
+      ComputedRelationship{relFunction} -> target == qiName relFunction
+      Relationship{..} ->
+        -- In a self-relationship we have a single foreign key but two relationships with different cardinalities: M2O/O2M. For disambiguation, we use the convention of getting:
+        -- TODO: handle one-to-one and many-to-many self-relationships
+        if relIsSelf
+        then case hint of
+          Nothing ->
+            -- The O2M by using the table name in the target
+            target == qiName relForeignTable && isO2M relCardinality -- /family_tree?select=children:family_tree(*)
+            ||
+            -- The M2O by using the column name in the target
+            matchFKSingleCol target relCardinality && isM2O relCardinality -- /family_tree?select=parent(*)
+          Just hnt ->
+            -- /organizations?select=auditees:organizations!auditor(*)
+            target == qiName relForeignTable && isO2M relCardinality
+            && matchFKRefSingleCol hnt relCardinality -- auditor
+        else case hint of
+          -- target = table / view / constraint / column-from-origin (constraint/column-from-origin can only come from tables https://github.com/PostgREST/postgrest/issues/2277)
+          -- hint   = table / view / constraint / column-from-origin / column-from-target (hint can take table / view values to aid in finding the junction in an m2m relationship)
+          Nothing ->
+              -- /projects?select=clients(*)
+              target == qiName relForeignTable -- clients
+              ||
+              -- /projects?select=projects_client_id_fkey(*)
+              matchConstraint target relCardinality -- projects_client_id_fkey
+              && not relFTableIsView
+              ||
+              -- /projects?select=client_id(*)
+              matchFKSingleCol target relCardinality -- client_id
+              && not relFTableIsView
+          Just hnt ->
+            -- /projects?select=clients(*)
+            target == qiName relForeignTable -- clients
+            && (
+              -- /projects?select=clients!projects_client_id_fkey(*)
+              matchConstraint hnt relCardinality || -- projects_client_id_fkey
+
+              -- /projects?select=clients!client_id(*) or /projects?select=clients!id(*)
+              matchFKSingleCol hnt relCardinality      || -- client_id
+              matchFKRefSingleCol hnt relCardinality   || -- id
+
+              -- /users?select=tasks!users_tasks(*) many-to-many between users and tasks
+              matchJunction hnt relCardinality -- users_tasks
+            )
+      ) $ fromMaybe mempty $ HM.lookup (QualifiedIdentifier schema origin, schema) allRels
+
+addFilters :: ApiRequest -> ReadPlanTree -> Either ApiRequestError ReadPlanTree
+addFilters ApiRequest{..} rReq =
+  foldr addFilterToNode (Right rReq) flts
+  where
+    QueryParams.QueryParams{..} = iQueryParams
+    flts =
+      case iAction of
+        ActionInvoke InvGet  -> qsFilters
+        ActionInvoke InvHead -> qsFilters
+        ActionInvoke _       -> qsFilters
+        ActionRead _         -> qsFilters
+        _                    -> qsFiltersNotRoot
+
+    addFilterToNode :: (EmbedPath, Filter) -> Either ApiRequestError ReadPlanTree ->  Either ApiRequestError ReadPlanTree
+    addFilterToNode =
+      updateNode (\flt (Node q@ReadPlan{where_=lf} f) -> Node q{ReadPlan.where_=addFilterToLogicForest flt lf}  f)
+
+addOrders :: ApiRequest -> ReadPlanTree -> Either ApiRequestError ReadPlanTree
+addOrders ApiRequest{..} rReq =
+  case iAction of
+    ActionMutate _ -> Right rReq
+    _              -> foldr addOrderToNode (Right rReq) qsOrder
+  where
+    QueryParams.QueryParams{..} = iQueryParams
+
+    addOrderToNode :: (EmbedPath, [OrderTerm]) -> Either ApiRequestError ReadPlanTree -> Either ApiRequestError ReadPlanTree
+    addOrderToNode = updateNode (\o (Node q f) -> Node q{order=o} f)
+
+addRanges :: ApiRequest -> ReadPlanTree -> Either ApiRequestError ReadPlanTree
+addRanges ApiRequest{..} rReq =
+  case iAction of
+    ActionMutate _ -> Right rReq
+    _              -> foldr addRangeToNode (Right rReq) =<< ranges
+  where
+    ranges :: Either ApiRequestError [(EmbedPath, NonnegRange)]
+    ranges = first QueryParamError $ QueryParams.pRequestRange `traverse` HM.toList iRange
+
+    addRangeToNode :: (EmbedPath, NonnegRange) -> Either ApiRequestError ReadPlanTree -> Either ApiRequestError ReadPlanTree
+    addRangeToNode = updateNode (\r (Node q f) -> Node q{range_=r} f)
+
+addLogicTrees :: ApiRequest -> ReadPlanTree -> Either ApiRequestError ReadPlanTree
+addLogicTrees ApiRequest{..} rReq =
+  foldr addLogicTreeToNode (Right rReq) qsLogic
+  where
+    QueryParams.QueryParams{..} = iQueryParams
+
+    addLogicTreeToNode :: (EmbedPath, LogicTree) -> Either ApiRequestError ReadPlanTree -> Either ApiRequestError ReadPlanTree
+    addLogicTreeToNode = updateNode (\t (Node q@ReadPlan{where_=lf} f) -> Node q{ReadPlan.where_=t:lf} f)
+
+-- Find a Node of the Tree and apply a function to it
+updateNode :: (a -> ReadPlanTree -> ReadPlanTree) -> (EmbedPath, a) -> Either ApiRequestError ReadPlanTree -> Either ApiRequestError ReadPlanTree
+updateNode f ([], a) rr = f a <$> rr
+updateNode _ _ (Left e) = Left e
+updateNode f (targetNodeName:remainingPath, a) (Right (Node rootNode forest)) =
+  case findNode of
+    Nothing -> Left $ NotEmbedded targetNodeName
+    Just target ->
+      (\node -> Node rootNode $ node : delete target forest) <$>
+      updateNode f (remainingPath, a) (Right target)
+  where
+    findNode :: Maybe ReadPlanTree
+    findNode = find (\(Node ReadPlan{relName, relAlias} _) -> relName == targetNodeName || relAlias == Just targetNodeName) forest
+
+mutatePlan :: Mutation -> QualifiedIdentifier -> ApiRequest -> SchemaCache -> ReadPlanTree -> Either Error MutatePlan
+mutatePlan mutation qi ApiRequest{..} sCache readReq = mapLeft ApiRequestError $
+  case mutation of
+    MutationCreate ->
+      Right $ Insert qi iColumns body ((,) <$> iPreferResolution <*> Just confCols) [] returnings pkCols
+    MutationUpdate -> Right $ Update qi iColumns body combinedLogic iTopLevelRange rootOrder returnings
+    MutationSingleUpsert ->
+        if null qsLogic &&
+           qsFilterFields == S.fromList pkCols &&
+           not (null (S.fromList pkCols)) &&
+           all (\case
+              Filter _ (OpExpr False (Op OpEqual _)) -> True
+              _                                      -> False) qsFiltersRoot
+          then Right $ Insert qi iColumns body (Just (MergeDuplicates, pkCols)) combinedLogic returnings mempty
+        else
+          Left InvalidFilters
+    MutationDelete -> Right $ Delete qi combinedLogic iTopLevelRange rootOrder returnings
+  where
+    confCols = fromMaybe pkCols qsOnConflict
+    QueryParams.QueryParams{..} = iQueryParams
+    returnings =
+      if iPreferRepresentation == None
+        then []
+        else inferColsEmbedNeeds readReq pkCols
+    pkCols = maybe mempty tablePKCols $ HM.lookup qi $ dbTables sCache
+    logic = map snd qsLogic
+    rootOrder = maybe [] snd $ find (\(x, _) -> null x) qsOrder
+    combinedLogic = foldr addFilterToLogicForest logic qsFiltersRoot
+    body = payRaw <$> iPayload -- the body is assumed to be json at this stage(ApiRequest validates)
+
+callPlan :: ProcDescription -> ApiRequest -> ReadPlanTree -> CallPlan
+callPlan proc apiReq readReq = FunctionCall {
+  funCQi = QualifiedIdentifier (pdSchema proc) (pdName proc)
+, funCParams = callParams
+, funCArgs = payRaw <$> iPayload apiReq
+, funCScalar = procReturnsScalar proc
+, funCMultipleCall = iPreferParameters apiReq == Just MultipleObjects
+, funCReturning = inferColsEmbedNeeds readReq []
+}
+  where
+    paramsAsSingleObject = iPreferParameters apiReq == Just SingleObject
+    callParams = case pdParams proc of
+      [prm] | paramsAsSingleObject -> OnePosParam prm
+            | ppName prm == mempty -> OnePosParam prm
+            | otherwise            -> KeyParams $ specifiedParams [prm]
+      prms  -> KeyParams $ specifiedParams prms
+    specifiedParams = filter (\x -> ppName x `S.member` iColumns apiReq)
+
+-- | Infers the columns needed for an embed to be successful after a mutation or a function call.
+inferColsEmbedNeeds :: ReadPlanTree -> [FieldName] -> [FieldName]
+inferColsEmbedNeeds (Node ReadPlan{select} forest) pkCols
+  -- if * is part of the select, we must not add pk or fk columns manually -
+  -- otherwise those would be selected and output twice
+  | "*" `elem` fldNames = ["*"]
+  | otherwise           = returnings
+  where
+    fldNames = (\((fld, _), _, _) -> fld) <$> select
+    -- Without fkCols, when a mutatePlan to
+    -- /projects?select=name,clients(name) occurs, the RETURNING SQL part would
+    -- be `RETURNING name`(see QueryBuilder).  This would make the embedding
+    -- fail because the following JOIN would need the "client_id" column from
+    -- projects.  So this adds the foreign key columns to ensure the embedding
+    -- succeeds, result would be `RETURNING name, client_id`.
+    fkCols = concat $ mapMaybe (\case
+        Node ReadPlan{relToParent=Just Relationship{relCardinality=O2M _ cols}} _ ->
+          Just $ fst <$> cols
+        Node ReadPlan{relToParent=Just Relationship{relCardinality=M2O _ cols}} _ ->
+          Just $ fst <$> cols
+        Node ReadPlan{relToParent=Just Relationship{relCardinality=O2O _ cols}} _ ->
+          Just $ fst <$> cols
+        Node ReadPlan{relToParent=Just Relationship{relCardinality=M2M Junction{junColsSource=cols}}} _ ->
+          Just $ fst <$> cols
+        Node ReadPlan{relToParent=Just ComputedRelationship{}} _ ->
+          Nothing
+        Node ReadPlan{relToParent=Nothing} _ ->
+          Nothing
+      ) forest
+    hasComputedRel = isJust $ find (\case
+      Node ReadPlan{relToParent=Just ComputedRelationship{}} _ -> True
+      _                                                    -> False
+      ) forest
+    -- However if the "client_id" is present, e.g. mutatePlan to
+    -- /projects?select=client_id,name,clients(name) we would get `RETURNING
+    -- client_id, name, client_id` and then we would produce the "column
+    -- reference \"client_id\" is ambiguous" error from PostgreSQL. So we
+    -- deduplicate with Set: We are adding the primary key columns as well to
+    -- make sure, that a proper location header can always be built for
+    -- INSERT/POST
+    returnings =
+      if not hasComputedRel
+        then S.toList . S.fromList $ fldNames ++ fkCols ++ pkCols
+        else ["*"] -- on computed relationships we cannot know the required columns for an embedding to succeed, so we just return all
+
+-- Traditional filters(e.g. id=eq.1) are added as root nodes of the LogicTree
+-- they are later concatenated with AND in the QueryBuilder
+addFilterToLogicForest :: Filter -> [LogicTree] -> [LogicTree]
+addFilterToLogicForest flt lf = Stmnt flt : lf
@@ -0,0 +1,25 @@
+module PostgREST.Plan.CallPlan
+  ( CallPlan(..)
+  , CallParams(..)
+  )
+where
+
+import qualified Data.ByteString.Lazy              as LBS
+import           PostgREST.SchemaCache.Identifiers (FieldName,
+                                                    QualifiedIdentifier)
+import           PostgREST.SchemaCache.Proc        (ProcParam (..))
+
+import Protolude
+
+data CallPlan = FunctionCall
+  { funCQi           :: QualifiedIdentifier
+  , funCParams       :: CallParams
+  , funCArgs         :: Maybe LBS.ByteString
+  , funCScalar       :: Bool
+  , funCMultipleCall :: Bool
+  , funCReturning    :: [FieldName]
+  }
+
+data CallParams
+  = KeyParams [ProcParam] -- ^ Call with key params: func(a := val1, b:= val2)
+  | OnePosParam ProcParam -- ^ Call with positional params(only one supported): func(val)
@@ -0,0 +1,42 @@
+module PostgREST.Plan.MutatePlan
+  ( MutatePlan(..)
+  )
+where
+
+import qualified Data.ByteString.Lazy as LBS
+import qualified Data.Set             as S
+
+import PostgREST.ApiRequest.Preferences  (PreferResolution)
+import PostgREST.ApiRequest.Types        (LogicTree, OrderTerm)
+import PostgREST.RangeQuery              (NonnegRange)
+import PostgREST.SchemaCache.Identifiers (FieldName,
+                                          QualifiedIdentifier)
+
+import Protolude
+
+data MutatePlan
+  = Insert
+      { in_        :: QualifiedIdentifier
+      , insCols    :: S.Set FieldName
+      , insBody    :: Maybe LBS.ByteString
+      , onConflict :: Maybe (PreferResolution, [FieldName])
+      , where_     :: [LogicTree]
+      , returning  :: [FieldName]
+      , insPkCols  :: [FieldName]
+      }
+  | Update
+      { in_       :: QualifiedIdentifier
+      , updCols   :: S.Set FieldName
+      , updBody   :: Maybe LBS.ByteString
+      , where_    :: [LogicTree]
+      , mutRange  :: NonnegRange
+      , mutOrder  :: [OrderTerm]
+      , returning :: [FieldName]
+      }
+  | Delete
+      { in_       :: QualifiedIdentifier
+      , where_    :: [LogicTree]
+      , mutRange  :: NonnegRange
+      , mutOrder  :: [OrderTerm]
+      , returning :: [FieldName]
+      }
@@ -0,0 +1,45 @@
+module PostgREST.Plan.ReadPlan
+  ( ReadPlanTree
+  , ReadPlan(..)
+  , JoinCondition(..)
+  ) where
+
+import Data.Tree (Tree (..))
+
+import PostgREST.ApiRequest.Types         (Alias, Cast, Depth, Field,
+                                           Hint, JoinType, LogicTree,
+                                           NodeName, OrderTerm)
+import PostgREST.RangeQuery               (NonnegRange)
+import PostgREST.SchemaCache.Identifiers  (FieldName,
+                                           QualifiedIdentifier)
+import PostgREST.SchemaCache.Relationship (Relationship)
+
+
+import Protolude
+
+type ReadPlanTree = Tree ReadPlan
+
+data JoinCondition =
+  JoinCondition
+    (QualifiedIdentifier, FieldName)
+    (QualifiedIdentifier, FieldName)
+  deriving (Eq)
+
+data ReadPlan = ReadPlan
+  { select       :: [(Field, Maybe Cast, Maybe Alias)]
+  , from         :: QualifiedIdentifier
+  , fromAlias    :: Maybe Alias
+  , where_       :: [LogicTree]
+  , order        :: [OrderTerm]
+  , range_       :: NonnegRange
+  , relName      :: NodeName
+  , relToParent  :: Maybe Relationship
+  , relJoinConds :: [JoinCondition]
+  , relAlias     :: Maybe Alias
+  , relAggAlias  :: Alias
+  , relHint      :: Maybe Hint
+  , relJoinType  :: Maybe JoinType
+  , depth        :: Depth
+  -- ^ used for aliasing
+  }
+  deriving (Eq)
@@ -0,0 +1,294 @@
+{-# LANGUAGE NamedFieldPuns  #-}
+{-# LANGUAGE RecordWildCards #-}
+module PostgREST.Query
+  ( createQuery
+  , deleteQuery
+  , invokeQuery
+  , openApiQuery
+  , readQuery
+  , singleUpsertQuery
+  , txMode
+  , updateQuery
+  , setPgLocals
+  , DbHandler
+  ) where
+
+import qualified Data.Aeson                        as JSON
+import qualified Data.Aeson.Key                    as K
+import qualified Data.Aeson.KeyMap                 as KM
+import qualified Data.ByteString.Lazy.Char8        as LBS
+import qualified Data.HashMap.Strict               as HM
+import qualified Data.Set                          as S
+import qualified Data.Text.Encoding                as T
+import qualified Hasql.Decoders                    as HD
+import qualified Hasql.DynamicStatements.Snippet   as SQL (Snippet)
+import qualified Hasql.DynamicStatements.Statement as SQL
+import qualified Hasql.Transaction                 as SQL
+import qualified Hasql.Transaction.Sessions        as SQL
+
+import qualified PostgREST.Error              as Error
+import qualified PostgREST.Query.QueryBuilder as QueryBuilder
+import qualified PostgREST.Query.Statements   as Statements
+import qualified PostgREST.RangeQuery         as RangeQuery
+import qualified PostgREST.SchemaCache        as SchemaCache
+import qualified PostgREST.SchemaCache.Proc   as Proc
+
+import Data.Scientific (FPFormat (..), formatScientific, isInteger)
+
+import PostgREST.ApiRequest              (Action (..),
+                                          ApiRequest (..),
+                                          InvokeMethod (..),
+                                          Target (..))
+import PostgREST.ApiRequest.Preferences  (PreferCount (..),
+                                          PreferParameters (..),
+                                          PreferTransaction (..),
+                                          shouldCount)
+import PostgREST.Config                  (AppConfig (..),
+                                          OpenAPIMode (..))
+import PostgREST.Config.PgVersion        (PgVersion (..),
+                                          pgVersion140)
+import PostgREST.Error                   (Error)
+import PostgREST.MediaType               (MediaType (..))
+import PostgREST.Plan                    (CallReadPlan (..),
+                                          MutateReadPlan (..))
+import PostgREST.Plan.MutatePlan         (MutatePlan (..))
+import PostgREST.Plan.ReadPlan           (ReadPlanTree)
+import PostgREST.Query.SqlFragment       (fromQi, intercalateSnippet,
+                                          pgFmtIdentList,
+                                          setConfigLocal,
+                                          setConfigLocalJson)
+import PostgREST.Query.Statements        (ResultSet (..))
+import PostgREST.SchemaCache             (SchemaCache (..))
+import PostgREST.SchemaCache.Identifiers (QualifiedIdentifier (..),
+                                          Schema)
+import PostgREST.SchemaCache.Proc        (ProcDescription (..),
+                                          ProcVolatility (..),
+                                          ProcsMap)
+import PostgREST.SchemaCache.Table       (TablesMap)
+
+import Protolude hiding (Handler)
+
+type DbHandler = ExceptT Error SQL.Transaction
+
+readQuery :: ReadPlanTree -> AppConfig -> ApiRequest -> DbHandler ResultSet
+readQuery req conf@AppConfig{..} apiReq@ApiRequest{..} = do
+  let countQuery = QueryBuilder.readPlanToCountQuery req
+  resultSet <-
+     lift . SQL.statement mempty $
+      Statements.prepareRead
+        (QueryBuilder.readPlanToQuery req)
+        (if iPreferCount == Just EstimatedCount then
+           -- LIMIT maxRows + 1 so we can determine below that maxRows was surpassed
+           QueryBuilder.limitedQuery countQuery ((+ 1) <$> configDbMaxRows)
+         else
+           countQuery
+        )
+        (shouldCount iPreferCount)
+        iAcceptMediaType
+        iBinaryField
+        configDbPreparedStatements
+  failNotSingular iAcceptMediaType resultSet
+  optionalRollback conf apiReq
+  resultSetWTotal conf apiReq resultSet countQuery
+
+resultSetWTotal :: AppConfig -> ApiRequest -> ResultSet -> SQL.Snippet -> DbHandler ResultSet
+resultSetWTotal _ _ rs@RSPlan{} _ = return rs
+resultSetWTotal AppConfig{..} ApiRequest{..} rs@RSStandard{rsTableTotal=tableTotal} countQuery =
+  case iPreferCount of
+    Just PlannedCount -> do
+      total <- explain
+      return rs{rsTableTotal=total}
+    Just EstimatedCount ->
+      if tableTotal > (fromIntegral <$> configDbMaxRows) then do
+        total <- max tableTotal <$> explain
+        return rs{rsTableTotal=total}
+      else
+        return rs
+    Just ExactCount ->
+      return rs
+    Nothing ->
+      return rs
+  where
+    explain =
+      lift . SQL.statement mempty . Statements.preparePlanRows countQuery $
+        configDbPreparedStatements
+
+createQuery :: MutateReadPlan -> ApiRequest -> AppConfig -> DbHandler ResultSet
+createQuery mrPlan apiReq@ApiRequest{..} conf = do
+  resultSet <- writeQuery mrPlan apiReq conf
+  failNotSingular iAcceptMediaType resultSet
+  optionalRollback conf apiReq
+  pure resultSet
+
+updateQuery :: MutateReadPlan -> ApiRequest -> AppConfig -> DbHandler ResultSet
+updateQuery mrPlan apiReq@ApiRequest{..} conf = do
+  resultSet <- writeQuery mrPlan apiReq conf
+  failNotSingular iAcceptMediaType resultSet
+  failsChangesOffLimits (RangeQuery.rangeLimit iTopLevelRange) resultSet
+  optionalRollback conf apiReq
+  pure resultSet
+
+singleUpsertQuery :: MutateReadPlan -> ApiRequest -> AppConfig -> DbHandler ResultSet
+singleUpsertQuery mrPlan apiReq conf = do
+  resultSet <- writeQuery mrPlan apiReq conf
+  failPut resultSet
+  optionalRollback conf apiReq
+  pure resultSet
+
+-- Makes sure the querystring pk matches the payload pk
+-- e.g. PUT /items?id=eq.1 { "id" : 1, .. } is accepted,
+-- PUT /items?id=eq.14 { "id" : 2, .. } is rejected.
+-- If this condition is not satisfied then nothing is inserted,
+-- check the WHERE for INSERT in QueryBuilder.hs to see how it's done
+failPut :: ResultSet -> DbHandler ()
+failPut RSPlan{} = pure ()
+failPut RSStandard{rsQueryTotal=queryTotal} =
+  when (queryTotal /= 1) $ do
+    lift SQL.condemn
+    throwError Error.PutMatchingPkError
+
+deleteQuery :: MutateReadPlan -> ApiRequest -> AppConfig -> DbHandler ResultSet
+deleteQuery mrPlan apiReq@ApiRequest{..} conf = do
+  resultSet <- writeQuery mrPlan apiReq conf
+  failNotSingular iAcceptMediaType resultSet
+  failsChangesOffLimits (RangeQuery.rangeLimit iTopLevelRange) resultSet
+  optionalRollback conf apiReq
+  pure resultSet
+
+invokeQuery :: ProcDescription -> CallReadPlan -> ApiRequest -> AppConfig -> DbHandler ResultSet
+invokeQuery proc CallReadPlan{crReadPlan, crCallPlan} apiReq@ApiRequest{..} conf@AppConfig{..} = do
+  resultSet <-
+    lift . SQL.statement mempty $
+      Statements.prepareCall
+        (Proc.procReturnsScalar proc)
+        (Proc.procReturnsSingle proc)
+        (QueryBuilder.callPlanToQuery crCallPlan)
+        (QueryBuilder.readPlanToQuery crReadPlan)
+        (QueryBuilder.readPlanToCountQuery crReadPlan)
+        (shouldCount iPreferCount)
+        iAcceptMediaType
+        (iPreferParameters == Just MultipleObjects)
+        iBinaryField
+        configDbPreparedStatements
+
+  optionalRollback conf apiReq
+  failNotSingular iAcceptMediaType resultSet
+  pure resultSet
+
+openApiQuery :: SchemaCache -> PgVersion -> AppConfig -> Schema -> DbHandler (Maybe (TablesMap, ProcsMap, Maybe Text))
+openApiQuery sCache pgVer AppConfig{..} tSchema =
+  lift $ case configOpenApiMode of
+    OAFollowPriv -> do
+      tableAccess <- SQL.statement [tSchema] (SchemaCache.accessibleTables pgVer configDbPreparedStatements)
+      Just <$> ((,,)
+            (HM.filterWithKey (\qi _ -> S.member qi tableAccess) $ SchemaCache.dbTables sCache)
+        <$> SQL.statement tSchema (SchemaCache.accessibleProcs pgVer configDbPreparedStatements)
+        <*> SQL.statement tSchema (SchemaCache.schemaDescription configDbPreparedStatements))
+    OAIgnorePriv ->
+      Just <$> ((,,)
+            (HM.filterWithKey (\(QualifiedIdentifier sch _) _ ->  sch == tSchema) $ SchemaCache.dbTables sCache)
+            (HM.filterWithKey (\(QualifiedIdentifier sch _) _ ->  sch == tSchema) $ SchemaCache.dbProcs sCache)
+        <$> SQL.statement tSchema (SchemaCache.schemaDescription configDbPreparedStatements))
+    OADisabled ->
+      pure Nothing
+
+txMode :: ApiRequest -> SQL.Mode
+txMode ApiRequest{..} =
+  case (iAction, iTarget) of
+    (ActionRead _, _) ->
+      SQL.Read
+    (ActionInspect _, _) ->
+      SQL.Read
+    (ActionInvoke InvGet, _) ->
+      SQL.Read
+    (ActionInvoke InvHead, _) ->
+      SQL.Read
+    (ActionInvoke InvPost, TargetProc ProcDescription{pdVolatility=Stable} _) ->
+      SQL.Read
+    (ActionInvoke InvPost, TargetProc ProcDescription{pdVolatility=Immutable} _) ->
+      SQL.Read
+    _ ->
+      SQL.Write
+
+writeQuery :: MutateReadPlan -> ApiRequest -> AppConfig  -> DbHandler ResultSet
+writeQuery MutateReadPlan{mrReadPlan, mrMutatePlan} apiReq conf =
+  let
+    (isInsert, pkCols) = case mrMutatePlan of {Insert{insPkCols} -> (True, insPkCols); _ -> (False, mempty);}
+  in
+  lift . SQL.statement mempty $
+    Statements.prepareWrite
+      (QueryBuilder.readPlanToQuery mrReadPlan)
+      (QueryBuilder.mutatePlanToQuery mrMutatePlan)
+      isInsert
+      (iAcceptMediaType apiReq)
+      (iPreferRepresentation apiReq)
+      pkCols
+      (configDbPreparedStatements conf)
+
+-- |
+-- Fail a response if a single JSON object was requested and not exactly one
+-- was found.
+failNotSingular :: MediaType -> ResultSet -> DbHandler ()
+failNotSingular _ RSPlan{} = pure ()
+failNotSingular mediaType RSStandard{rsQueryTotal=queryTotal} =
+  when (mediaType == MTSingularJSON && queryTotal /= 1) $ do
+    lift SQL.condemn
+    throwError $ Error.singularityError queryTotal
+
+failsChangesOffLimits :: Maybe Integer -> ResultSet -> DbHandler ()
+failsChangesOffLimits _ RSPlan{} = pure ()
+failsChangesOffLimits Nothing _  = pure ()
+failsChangesOffLimits (Just maxChanges) RSStandard{rsQueryTotal=queryTotal} =
+  when (queryTotal > fromIntegral maxChanges) $ do
+    lift SQL.condemn
+    throwError $ Error.OffLimitsChangesError queryTotal maxChanges
+
+-- | Set a transaction to roll back if requested
+optionalRollback :: AppConfig -> ApiRequest -> DbHandler ()
+optionalRollback AppConfig{..} ApiRequest{..} = do
+  lift $ when (shouldRollback || (configDbTxRollbackAll && not shouldCommit)) $ do
+    SQL.sql "SET CONSTRAINTS ALL IMMEDIATE"
+    SQL.condemn
+  where
+    shouldCommit =
+      configDbTxAllowOverride && iPreferTransaction == Just Commit
+    shouldRollback =
+      configDbTxAllowOverride && iPreferTransaction == Just Rollback
+
+-- | Runs local(transaction scoped) GUCs for every request, plus the pre-request function
+setPgLocals :: AppConfig   -> KM.KeyMap JSON.Value -> Text ->
+               ApiRequest  -> ByteString -> PgVersion -> DbHandler ()
+setPgLocals conf claims role req jsonDbS actualPgVersion = do
+  lift $ SQL.statement mempty $ SQL.dynamicallyParameterized
+    ("select " <> intercalateSnippet ", " (searchPathSql : roleSql ++ claimsSql ++ [methodSql, pathSql] ++ headersSql ++ cookiesSql ++ appSettingsSql ++ specSql))
+    HD.noResult (configDbPreparedStatements conf)
+  lift $ traverse_ SQL.sql preReqSql
+  where
+    methodSql = setConfigLocal mempty ("request.method", iMethod req)
+    pathSql = setConfigLocal mempty ("request.path", iPath req)
+    headersSql = if usesLegacyGucs
+                   then setConfigLocal "request.header." <$> iHeaders req
+                   else setConfigLocalJson "request.headers" (iHeaders req)
+    cookiesSql = if usesLegacyGucs
+                   then setConfigLocal "request.cookie." <$> iCookies req
+                   else setConfigLocalJson "request.cookies" (iCookies req)
+    claimsSql = if usesLegacyGucs
+                  then setConfigLocal "request.jwt.claim." <$> [(toUtf8 $ K.toText c, toUtf8 $ unquoted v) | (c,v) <- KM.toList claims]
+                  else [setConfigLocal mempty ("request.jwt.claims", LBS.toStrict $ JSON.encode claims)]
+    roleSql = [setConfigLocal mempty ("role", toUtf8 role)]
+    appSettingsSql = setConfigLocal mempty <$> (join bimap toUtf8 <$> configAppSettings conf)
+    searchPathSql =
+      let schemas = pgFmtIdentList (iSchema req : configDbExtraSearchPath conf) in
+      setConfigLocal mempty ("search_path", schemas)
+    preReqSql = (\f -> "select " <> fromQi f <> "();") <$> configDbPreRequest conf
+    specSql = case iTarget req of
+      TargetProc{tpIsRootSpec=True} -> [setConfigLocal mempty ("request.spec", jsonDbS)]
+      _                             -> mempty
+    usesLegacyGucs = configDbUseLegacyGucs conf && actualPgVersion < pgVersion140
+
+    unquoted :: JSON.Value -> Text
+    unquoted (JSON.String t) = t
+    unquoted (JSON.Number n) =
+      toS $ formatScientific Fixed (if isInteger n then Just 0 else Nothing) n
+    unquoted (JSON.Bool b) = show b
+    unquoted v = T.decodeUtf8 . LBS.toStrict $ JSON.encode v
@@ -1,17 +1,18 @@
 {-# LANGUAGE DuplicateRecordFields #-}
+{-# LANGUAGE NamedFieldPuns        #-}
 {-|
 Module      : PostgREST.Query.QueryBuilder
 Description : PostgREST SQL queries generating functions.

 This module provides functions to consume data types that
-represent database queries (e.g. ReadRequest, MutateRequest) and SqlFragment
+represent database queries (e.g. ReadPlanTree, MutatePlan) and SqlFragment
 to produce SqlQuery type outputs.
 -}
 module PostgREST.Query.QueryBuilder
-  ( readRequestToQuery
-  , mutateRequestToQuery
-  , readRequestToCountQuery
-  , requestToCallProcQuery
+  ( readPlanToQuery
+  , mutatePlanToQuery
+  , readPlanToCountQuery
+  , callPlanToQuery
  , limitedQuery
  ) where

@@ -21,67 +22,67 @@ import qualified Hasql.DynamicStatements.Snippet as SQL

 import Data.Tree (Tree (..))

-import PostgREST.DbStructure.Identifiers  (QualifiedIdentifier (..))
-import PostgREST.DbStructure.Proc         (ProcParam (..))
-import PostgREST.DbStructure.Relationship (Cardinality (..),
+import PostgREST.ApiRequest.Preferences   (PreferResolution (..))
+import PostgREST.SchemaCache.Identifiers  (QualifiedIdentifier (..))
+import PostgREST.SchemaCache.Proc         (ProcParam (..))
+import PostgREST.SchemaCache.Relationship (Cardinality (..),
+                                           Junction (..),
                                           Relationship (..))
-import PostgREST.DbStructure.Table        (Table (..))
-import PostgREST.Request.Preferences      (PreferResolution (..))

+import PostgREST.ApiRequest.Types
+import PostgREST.Plan.CallPlan
+import PostgREST.Plan.MutatePlan
+import PostgREST.Plan.ReadPlan
 import PostgREST.Query.SqlFragment
-import PostgREST.Request.Types
+import PostgREST.RangeQuery        (allRange)

 import Protolude

-readRequestToQuery :: ReadRequest -> SQL.Snippet
-readRequestToQuery (Node (Select colSelects mainQi tblAlias implJoins logicForest joinConditions_ ordts range, _) forest) =
+readPlanToQuery :: ReadPlanTree -> SQL.Snippet
+readPlanToQuery (Node ReadPlan{select,from=mainQi,fromAlias,where_=logicForest,order, range_=readRange, relToParent, relJoinConds} forest) =
  "SELECT " <>
-  intercalateSnippet ", " ((pgFmtSelectItem qi <$> colSelects) ++ selects) <>
-  "FROM " <> SQL.sql (BS.intercalate ", " (tabl : implJs)) <> " " <>
+  intercalateSnippet ", " ((pgFmtSelectItem qi <$> select) ++ selects) <> " " <>
+  fromFrag <> " " <>
  intercalateSnippet " " joins <> " " <>
-  (if null logicForest && null joinConditions_ then mempty else "WHERE " <> intercalateSnippet " AND " (map (pgFmtLogicTree qi) logicForest ++ map pgFmtJoinCondition joinConditions_))
-  <> " " <>
-  (if null ordts then mempty else "ORDER BY " <> intercalateSnippet ", " (map (pgFmtOrderTerm qi) ordts)) <> " " <>
-  limitOffsetF range
+  (if null logicForest && null relJoinConds
+    then mempty
+    else "WHERE " <> intercalateSnippet " AND " (map (pgFmtLogicTree qi) logicForest ++ map pgFmtJoinCondition relJoinConds)) <> " " <>
+  orderF qi order <> " " <>
+  limitOffsetF readRange
  where
-    implJs = fromQi <$> implJoins
-    tabl = fromQi mainQi <> maybe mempty (\a -> " AS " <> pgFmtIdent a) tblAlias
-    qi = maybe mainQi (QualifiedIdentifier mempty) tblAlias
-    (joins, selects) = foldr getJoinsSelects ([],[]) forest
+    fromFrag = fromF relToParent mainQi fromAlias
+    qi = getQualifiedIdentifier relToParent mainQi fromAlias
+    (selects, joins) = foldr getSelectsJoins ([],[]) forest

-getJoinsSelects :: ReadRequest -> ([SQL.Snippet], [SQL.Snippet]) -> ([SQL.Snippet], [SQL.Snippet])
-getJoinsSelects rr@(Node (_, (name, Just Relationship{relCardinality=card,relTable=Table{tableName=table}}, alias, _, joinType, _)) _) (joins,selects) =
-  let subquery = readRequestToQuery rr in
-  case card of
-    M2O _ ->
-      let aliasOrName = fromMaybe name alias
-          localTableName = pgFmtIdent $ table <> "_" <> aliasOrName
-          sel = SQL.sql ("row_to_json(" <> localTableName <> ".*) AS " <> pgFmtIdent aliasOrName)
-          joi = (if joinType == Just JTInner then " INNER" else " LEFT")
-            <> " JOIN LATERAL( " <> subquery <> " ) AS " <> SQL.sql localTableName <> " ON TRUE " in
-      (joi:joins,sel:selects)
-    _ -> case joinType of
-      Just JTInner ->
-        let aliasOrName = fromMaybe name alias
-            locTblName = table <> "_" <> aliasOrName
-            localTableName = pgFmtIdent locTblName
-            internalTableName = pgFmtIdent $ "_" <> locTblName
-            sel = SQL.sql $ localTableName <> "." <> internalTableName <> " AS " <> pgFmtIdent aliasOrName
-            joi = "INNER JOIN LATERAL(" <>
-                    "SELECT json_agg(" <> SQL.sql internalTableName <> ") AS " <> SQL.sql internalTableName <>
-                    "FROM (" <> subquery <> " ) AS " <> SQL.sql internalTableName <>
-                  ") AS " <> SQL.sql localTableName <> " ON " <> SQL.sql localTableName <> "IS NOT NULL" in
-        (joi:joins,sel:selects)
-      _ ->
-        let sel = "COALESCE (("
-               <> "SELECT json_agg(" <> SQL.sql (pgFmtIdent table) <> ".*) "
-               <> "FROM (" <> subquery <> ") " <> SQL.sql (pgFmtIdent table) <> " "
-               <> "), '[]') AS " <> SQL.sql (pgFmtIdent (fromMaybe name alias)) in
-        (joins,sel:selects)
-getJoinsSelects (Node (_, (_, Nothing, _, _, _, _)) _) _ = ([], [])
+getSelectsJoins :: ReadPlanTree -> ([SQL.Snippet], [SQL.Snippet]) -> ([SQL.Snippet], [SQL.Snippet])
+getSelectsJoins (Node ReadPlan{relToParent=Nothing} _) _ = ([], [])
+getSelectsJoins rr@(Node ReadPlan{relName, relToParent=Just rel, relAggAlias, relAlias, relJoinType=joinType} _) (selects,joins) =
+  let
+    subquery = readPlanToQuery rr
+    aliasOrName = pgFmtIdent $ fromMaybe relName relAlias
+    aggAlias = pgFmtIdent relAggAlias
+    correlatedSubquery sub al cond =
+      (if joinType == Just JTInner then "INNER" else "LEFT") <> " JOIN LATERAL ( " <> sub <> " ) AS " <> SQL.sql al <> " ON " <> cond
+    isToOne = case rel of
+      Relationship{relCardinality=M2O _ _} -> True
+      Relationship{relCardinality=O2O _ _} -> True
+      ComputedRelationship{relToOne=True}  -> True
+      _                                    -> False
+    (sel, joi) = if isToOne
+      then
+        ( SQL.sql ("row_to_json(" <> aggAlias <> ".*) AS " <> aliasOrName)
+        , correlatedSubquery subquery aggAlias "TRUE")
+      else
+        ( SQL.sql $ "COALESCE( " <> aggAlias <> "." <> aggAlias <> ", '[]') AS " <> aliasOrName
+        , correlatedSubquery (
+            "SELECT json_agg(" <> SQL.sql aggAlias <> ") AS " <> SQL.sql aggAlias <>
+            "FROM (" <> subquery <> " ) AS " <> SQL.sql aggAlias
+          ) aggAlias $ if joinType == Just JTInner then SQL.sql aggAlias <> " IS NOT NULL" else "TRUE")
+  in
+  (sel:selects, joi:joins)

-mutateRequestToQuery :: MutateRequest -> SQL.Snippet
-mutateRequestToQuery (Insert mainQi iCols body onConflct putConditions returnings) =
+mutatePlanToQuery :: MutatePlan -> SQL.Snippet
+mutatePlanToQuery (Insert mainQi iCols body onConflct putConditions returnings _) =
  "WITH " <> normalizedBody body <> " " <>
  "INSERT INTO " <> SQL.sql (fromQi mainQi) <> SQL.sql (if S.null iCols then " " else "(" <> cols <> ") ") <>
  "SELECT " <> SQL.sql cols <> " " <>
@@ -93,7 +94,7 @@ mutateRequestToQuery (Insert mainQi iCols body onConflct putConditions returning
      if null oncCols then
        mempty
      else
-        "ON CONFLICT(" <> BS.intercalate ", " (pgFmtIdent <$> oncCols) <> ") " <> case oncDo of
+        " ON CONFLICT(" <> BS.intercalate ", " (pgFmtIdent <$> oncCols) <> ") " <> case oncDo of
        IgnoreDuplicates ->
          "DO NOTHING"
        MergeDuplicates  ->
@@ -105,31 +106,69 @@ mutateRequestToQuery (Insert mainQi iCols body onConflct putConditions returning
    ])
  where
    cols = BS.intercalate ", " $ pgFmtIdent <$> S.toList iCols
-mutateRequestToQuery (Update mainQi uCols body logicForest returnings) =
-  if S.null uCols
+
+-- An update without a limit is always filtered with a WHERE
+mutatePlanToQuery (Update mainQi uCols body logicForest range ordts returnings)
+  | S.null uCols =
    -- if there are no columns we cannot do UPDATE table SET {empty}, it'd be invalid syntax
    -- selecting an empty resultset from mainQi gives us the column names to prevent errors when using &select=
    -- the select has to be based on "returnings" to make computed overloaded functions not throw
-    then SQL.sql ("SELECT " <> emptyBodyReturnedColumns <> " FROM " <> fromQi mainQi <> " WHERE false")
-    else
-      "WITH " <> normalizedBody body <> " " <>
-      "UPDATE " <> SQL.sql (fromQi mainQi) <> " SET " <> SQL.sql cols <> " " <>
-      "FROM (SELECT * FROM json_populate_recordset (null::" <> SQL.sql (fromQi mainQi) <> " , " <> SQL.sql selectBody <> " )) _ " <>
-      (if null logicForest then mempty else "WHERE " <> intercalateSnippet " AND " (pgFmtLogicTree mainQi <$> logicForest)) <> " " <>
-      SQL.sql (returningF mainQi returnings)
-  where
-    cols = BS.intercalate ", " (pgFmtIdent <> const " = _." <> pgFmtIdent <$> S.toList uCols)
-    emptyBodyReturnedColumns :: SqlFragment
-    emptyBodyReturnedColumns
-      | null returnings = "NULL"
-      | otherwise       = BS.intercalate ", " (pgFmtColumn (QualifiedIdentifier mempty $ qiName mainQi) <$> returnings)
-mutateRequestToQuery (Delete mainQi logicForest returnings) =
-  "DELETE FROM " <> SQL.sql (fromQi mainQi) <> " " <>
-  (if null logicForest then mempty else "WHERE " <> intercalateSnippet " AND " (map (pgFmtLogicTree mainQi) logicForest)) <> " " <>
-  SQL.sql (returningF mainQi returnings)
+    SQL.sql $ "SELECT " <> emptyBodyReturnedColumns <> " FROM " <> fromQi mainQi <> " WHERE false"

-requestToCallProcQuery :: CallRequest -> SQL.Snippet
-requestToCallProcQuery (FunctionCall qi params args returnsScalar multipleCall returnings) =
+  | range == allRange =
+    "WITH " <> normalizedBody body <> " " <>
+    "UPDATE " <> mainTbl <> " SET " <> SQL.sql nonRangeCols <> " " <>
+    "FROM (SELECT * FROM json_populate_recordset (null::" <> mainTbl <> " , " <> SQL.sql selectBody <> " )) _ " <>
+    whereLogic <> " " <>
+    SQL.sql (returningF mainQi returnings)
+
+  | otherwise =
+    "WITH " <> normalizedBody body <> ", " <>
+    "pgrst_update_body AS (SELECT * FROM json_populate_recordset (null::" <> mainTbl <> " , " <> SQL.sql selectBody <> " ) LIMIT 1), " <>
+    "pgrst_affected_rows AS (" <>
+      "SELECT " <> SQL.sql rangeIdF <> " FROM " <> mainTbl <>
+      whereLogic <> " " <>
+      orderF mainQi ordts <> " " <>
+      limitOffsetF range <>
+    ") " <>
+    "UPDATE " <> mainTbl <> " SET " <> SQL.sql rangeCols <>
+    "FROM pgrst_affected_rows " <>
+    "WHERE " <> SQL.sql whereRangeIdF <> " " <>
+    SQL.sql (returningF mainQi returnings)
+
+  where
+    whereLogic = if null logicForest then mempty else " WHERE " <> intercalateSnippet " AND " (pgFmtLogicTree mainQi <$> logicForest)
+    mainTbl = SQL.sql (fromQi mainQi)
+    emptyBodyReturnedColumns = if null returnings then "NULL" else BS.intercalate ", " (pgFmtColumn (QualifiedIdentifier mempty $ qiName mainQi) <$> returnings)
+    nonRangeCols = BS.intercalate ", " (pgFmtIdent <> const " = _." <> pgFmtIdent <$> S.toList uCols)
+    rangeCols = BS.intercalate ", " ((\col -> pgFmtIdent col <> " = (SELECT " <> pgFmtIdent col <> " FROM pgrst_update_body) ") <$> S.toList uCols)
+    (whereRangeIdF, rangeIdF) = mutRangeF mainQi (fst . otTerm <$> ordts)
+
+mutatePlanToQuery (Delete mainQi logicForest range ordts returnings)
+  | range == allRange =
+    "DELETE FROM " <> SQL.sql (fromQi mainQi) <> " " <>
+    whereLogic <> " " <>
+    SQL.sql (returningF mainQi returnings)
+
+  | otherwise =
+    "WITH " <>
+    "pgrst_affected_rows AS (" <>
+      "SELECT " <> SQL.sql rangeIdF <> " FROM " <> SQL.sql (fromQi mainQi) <>
+       whereLogic <> " " <>
+      orderF mainQi ordts <> " " <>
+      limitOffsetF range <>
+    ") " <>
+    "DELETE FROM " <> SQL.sql (fromQi mainQi) <> " " <>
+    "USING pgrst_affected_rows " <>
+    "WHERE " <> SQL.sql whereRangeIdF <> " " <>
+    SQL.sql (returningF mainQi returnings)
+
+  where
+    whereLogic = if null logicForest then mempty else " WHERE " <> intercalateSnippet " AND " (pgFmtLogicTree mainQi <$> logicForest)
+    (whereRangeIdF, rangeIdF) = mutRangeF mainQi (fst . otTerm <$> ordts)
+
+callPlanToQuery :: CallPlan -> SQL.Snippet
+callPlanToQuery (FunctionCall qi params args returnsScalar multipleCall returnings) =
  prmsCTE <> argsBody
  where
    (prmsCTE, argFrag) = case params of
@@ -183,24 +222,43 @@ requestToCallProcQuery (FunctionCall qi params args returnsScalar multipleCall r
 -- For this case, we use a WHERE EXISTS instead of an INNER JOIN on the count query.
 -- See https://github.com/PostgREST/postgrest/issues/2009#issuecomment-977473031
 -- Only for the nodes that have an INNER JOIN linked to the root level.
-readRequestToCountQuery :: ReadRequest -> SQL.Snippet
-readRequestToCountQuery (Node (Select{from=qi, implicitJoins=implJoins, where_=logicForest, joinConditions=joinConditions_}, _) forest) =
-  "SELECT 1 FROM " <> SQL.sql (BS.intercalate ", " (fromQi qi:(fromQi <$> implJoins))) <>
-  (if null logicForest && null joinConditions_ && null subQueries
+readPlanToCountQuery :: ReadPlanTree -> SQL.Snippet
+readPlanToCountQuery (Node ReadPlan{from=mainQi, fromAlias=tblAlias, where_=logicForest, relToParent=rel, relJoinConds} forest) =
+  "SELECT 1 " <> fromFrag <>
+  (if null logicForest && null relJoinConds && null subQueries
    then mempty
    else " WHERE " ) <>
  intercalateSnippet " AND " (
    map (pgFmtLogicTree qi) logicForest ++
-    map pgFmtJoinCondition joinConditions_ ++
+    map pgFmtJoinCondition relJoinConds ++
    subQueries
  )
  where
+    qi = getQualifiedIdentifier rel mainQi tblAlias
+    fromFrag = fromF rel mainQi tblAlias
    subQueries = foldr existsSubquery [] forest
-    existsSubquery :: ReadRequest -> [SQL.Snippet] -> [SQL.Snippet]
-    existsSubquery readReq@(Node (_, (_, _, _, _, joinType, _)) _) rest =
+    existsSubquery :: ReadPlanTree -> [SQL.Snippet] -> [SQL.Snippet]
+    existsSubquery readReq@(Node ReadPlan{relJoinType=joinType} _) rest =
      if joinType == Just JTInner
-        then ("EXISTS (" <> readRequestToCountQuery readReq <> " )"):rest
-        else mempty
+        then ("EXISTS (" <> readPlanToCountQuery readReq <> " )"):rest
+        else rest

 limitedQuery :: SQL.Snippet -> Maybe Integer -> SQL.Snippet
 limitedQuery query maxRows = query <> SQL.sql (maybe mempty (\x -> " LIMIT " <> BS.pack (show x)) maxRows)
+
+-- TODO refactor so this function is uneeded and ComputedRelationship QualifiedIdentifier comes from the ReadPlan type
+getQualifiedIdentifier :: Maybe Relationship -> QualifiedIdentifier -> Maybe Alias -> QualifiedIdentifier
+getQualifiedIdentifier rel mainQi tblAlias = case rel of
+  Just ComputedRelationship{relFunction} -> QualifiedIdentifier mempty $ fromMaybe (qiName relFunction) tblAlias
+  _                                      -> maybe mainQi (QualifiedIdentifier mempty) tblAlias
+
+-- FROM clause plus implicit joins
+fromF :: Maybe Relationship -> QualifiedIdentifier -> Maybe Alias -> SQL.Snippet
+fromF rel mainQi tblAlias = SQL.sql $ "FROM " <>
+  (case rel of
+    Just ComputedRelationship{relFunction,relTable} -> fromQi relFunction <> "(" <> pgFmtIdent (qiName relTable) <> ")"
+    _                                               -> fromQi mainQi) <>
+  maybe mempty (\a -> " AS " <> pgFmtIdent a) tblAlias <>
+  (case rel of
+    Just Relationship{relCardinality=M2M Junction{junTable=jt}} -> ", " <> fromQi jt
+    _                                                           -> mempty)
@@ -1,5 +1,6 @@
-{-# LANGUAGE LambdaCase  #-}
-{-# LANGUAGE QuasiQuotes #-}
+{-# LANGUAGE LambdaCase     #-}
+{-# LANGUAGE NamedFieldPuns #-}
+{-# LANGUAGE QuasiQuotes    #-}
 {-|
 Module      : PostgREST.Query.SqlFragment
 Description : Helper functions for PostgREST.QueryBuilder.
@@ -11,17 +12,20 @@ module PostgREST.Query.SqlFragment
  , SqlFragment
  , asBinaryF
  , asCsvF
+  , asGeoJsonF
  , asJsonF
  , asJsonSingleF
+  , asXmlF
  , countF
  , fromQi
-  , ftsOperators
  , limitOffsetF
  , locationF
+  , mutRangeF
  , normalizedBody
-  , operators
+  , orderF
  , pgFmtColumn
  , pgFmtIdent
+  , pgFmtIdentList
  , pgFmtJoinCondition
  , pgFmtLogicTree
  , pgFmtOrderTerm
@@ -34,24 +38,28 @@ module PostgREST.Query.SqlFragment
  , sourceCTEName
  , unknownEncoder
  , intercalateSnippet
+  , explainF
+  , setConfigLocal
+  , setConfigLocalJson
  ) where

+import qualified Data.Aeson                      as JSON
 import qualified Data.ByteString.Char8           as BS
 import qualified Data.ByteString.Lazy            as LBS
-import qualified Data.HashMap.Strict             as M
+import qualified Data.HashMap.Strict             as HM
 import qualified Data.Text                       as T
+import qualified Data.Text.Encoding              as T
 import qualified Hasql.DynamicStatements.Snippet as SQL
 import qualified Hasql.Encoders                  as HE

+import Control.Arrow ((***))
+
 import Data.Foldable                 (foldr1)
 import Text.InterpolatedString.Perl6 (qc)

-import PostgREST.DbStructure.Identifiers (FieldName,
-                                          QualifiedIdentifier (..))
-import PostgREST.RangeQuery              (NonnegRange, allRange,
-                                          rangeLimit, rangeOffset)
-import PostgREST.Request.Types           (Alias, Field, Filter (..),
-                                          JoinCondition (..),
+import PostgREST.ApiRequest.Types        (Alias, Cast, Field,
+                                          Filter (..),
+                                          FtsOperator (..),
                                          JsonOperand (..),
                                          JsonOperation (..),
                                          JsonPath,
@@ -60,8 +68,16 @@ import PostgREST.Request.Types           (Alias, Field, Filter (..),
                                          Operation (..),
                                          OrderDirection (..),
                                          OrderNulls (..),
-                                          OrderTerm (..), SelectItem,
+                                          OrderTerm (..),
+                                          SimpleOperator (..),
                                          TrileanVal (..))
+import PostgREST.MediaType               (MTPlanFormat (..),
+                                          MTPlanOption (..))
+import PostgREST.Plan.ReadPlan           (JoinCondition (..))
+import PostgREST.RangeQuery              (NonnegRange, allRange,
+                                          rangeLimit, rangeOffset)
+import PostgREST.SchemaCache.Identifiers (FieldName,
+                                          QualifiedIdentifier (..))

 import Protolude hiding (cast)

@@ -75,34 +91,33 @@ noLocationF = "array[]::text[]"
 sourceCTEName :: SqlFragment
 sourceCTEName = "pgrst_source"

-operators :: M.HashMap Text SqlFragment
-operators = M.union (M.fromList [
-  ("eq", "="),
-  ("gte", ">="),
-  ("gt", ">"),
-  ("lte", "<="),
-  ("lt", "<"),
-  ("neq", "<>"),
-  ("like", "LIKE"),
-  ("ilike", "ILIKE"),
-  ("in", "IN"),
-  ("is", "IS"),
-  ("cs", "@>"),
-  ("cd", "<@"),
-  ("ov", "&&"),
-  ("sl", "<<"),
-  ("sr", ">>"),
-  ("nxr", "&<"),
-  ("nxl", "&>"),
-  ("adj", "-|-")]) ftsOperators
+singleValOperator :: SimpleOperator -> SqlFragment
+singleValOperator = \case
+  OpEqual            -> "="
+  OpGreaterThanEqual -> ">="
+  OpGreaterThan      -> ">"
+  OpLessThanEqual    -> "<="
+  OpLessThan         -> "<"
+  OpNotEqual         -> "<>"
+  OpLike             -> "like"
+  OpILike            -> "ilike"
+  OpContains         -> "@>"
+  OpContained        -> "<@"
+  OpOverlap          -> "&&"
+  OpStrictlyLeft     -> "<<"
+  OpStrictlyRight    -> ">>"
+  OpNotExtendsRight  -> "&<"
+  OpNotExtendsLeft   -> "&>"
+  OpAdjacent         -> "-|-"
+  OpMatch            -> "~"
+  OpIMatch           -> "~*"

-ftsOperators :: M.HashMap Text SqlFragment
-ftsOperators = M.fromList [
-  ("fts", "@@ to_tsquery"),
-  ("plfts", "@@ plainto_tsquery"),
-  ("phfts", "@@ phraseto_tsquery"),
-  ("wfts", "@@ websearch_to_tsquery")
-  ]
+ftsOperator :: FtsOperator -> SqlFragment
+ftsOperator = \case
+  FilterFts          -> "@@ to_tsquery"
+  FilterFtsPlain     -> "@@ plainto_tsquery"
+  FilterFtsPhrase    -> "@@ phraseto_tsquery"
+  FilterFtsWebsearch -> "@@ websearch_to_tsquery"

 -- |
 -- These CTEs convert a json object into a json array, this way we can use json_populate_recordset for all json payloads
@@ -121,7 +136,7 @@ normalizedBody body =
        "END AS val",
      "FROM pgrst_payload)"])
  where
-    jsonPlaceHolder = SQL.encoderAndParam (HE.nullable HE.unknown) (LBS.toStrict <$> body) <> "::json"
+    jsonPlaceHolder = SQL.encoderAndParam (HE.nullable HE.jsonLazyBytes) body

 singleParameter :: Maybe LBS.ByteString -> ByteString -> SQL.Snippet
 singleParameter body typ =
@@ -153,6 +168,14 @@ pgFmtIdent x = encodeUtf8 $ "\"" <> T.replace "\"" "\"\"" (trimNullChars x) <> "
 trimNullChars :: Text -> Text
 trimNullChars = T.takeWhile (/= '\x0')

+-- |
+-- Format a list of identifiers and separate them by commas.
+--
+-- >>> pgFmtIdentList ["schema_1", "schema_2", "SPECIAL \"@/\\#~_-"]
+-- "\"schema_1\", \"schema_2\", \"SPECIAL \"\"@/\\#~_-\""
+pgFmtIdentList :: [Text] -> SqlFragment
+pgFmtIdentList schemas = BS.intercalate ", " $ pgFmtIdent <$> schemas
+
 asCsvF :: SqlFragment
 asCsvF = asCsvHeaderF <> " || '\n' || " <> asCsvBodyF
  where
@@ -172,10 +195,16 @@ asJsonF returnsScalar
  | returnsScalar = "coalesce(json_agg(_postgrest_t.pgrst_scalar), '[]')::character varying"
  | otherwise     = "coalesce(json_agg(_postgrest_t), '[]')::character varying"

-asJsonSingleF :: Bool -> SqlFragment --TODO! unsafe when the query actually returns multiple rows, used only on inserting and returning single element
+asJsonSingleF :: Bool -> SqlFragment
 asJsonSingleF returnsScalar
-  | returnsScalar = "coalesce(string_agg(to_json(_postgrest_t.pgrst_scalar)::text, ','), 'null')::character varying"
-  | otherwise     = "coalesce(string_agg(to_json(_postgrest_t)::text, ','), '')::character varying"
+  | returnsScalar = "coalesce((json_agg(_postgrest_t.pgrst_scalar)->0)::text, 'null')"
+  | otherwise     = "coalesce((json_agg(_postgrest_t)->0)::text, 'null')"
+
+asXmlF :: FieldName -> SqlFragment
+asXmlF fieldName = "coalesce(xmlagg(_postgrest_t." <> pgFmtIdent fieldName <> "), '')"
+
+asGeoJsonF ::  SqlFragment
+asGeoJsonF = "json_build_object('type', 'FeatureCollection', 'features', coalesce(json_agg(ST_AsGeoJSON(_postgrest_t)::json), '[]'))"

 asBinaryF :: FieldName -> SqlFragment
 asBinaryF fieldName = "coalesce(string_agg(_postgrest_t." <> pgFmtIdent fieldName <> ", ''), '')"
@@ -201,14 +230,17 @@ pgFmtColumn table "*" = fromQi table <> ".*"
 pgFmtColumn table c   = fromQi table <> "." <> pgFmtIdent c

 pgFmtField :: QualifiedIdentifier -> Field -> SQL.Snippet
-pgFmtField table (c, jp) = SQL.sql (pgFmtColumn table c) <> pgFmtJsonPath jp
+pgFmtField table (c, []) = SQL.sql (pgFmtColumn table c)
+-- Using to_jsonb instead of to_json to avoid missing operator errors when filtering:
+-- "operator does not exist: json = unknown"
+pgFmtField table (c, jp) = SQL.sql ("to_jsonb(" <> pgFmtColumn table c <> ")") <> pgFmtJsonPath jp

-pgFmtSelectItem :: QualifiedIdentifier -> SelectItem -> SQL.Snippet
-pgFmtSelectItem table (f@(fName, jp), Nothing, alias, _, _) = pgFmtField table f <> SQL.sql (pgFmtAs fName jp alias)
+pgFmtSelectItem :: QualifiedIdentifier -> (Field, Maybe Cast, Maybe Alias) -> SQL.Snippet
+pgFmtSelectItem table (f@(fName, jp), Nothing, alias) = pgFmtField table f <> SQL.sql (pgFmtAs fName jp alias)
 -- Ideally we'd quote the cast with "pgFmtIdent cast". However, that would invalidate common casts such as "int", "bigint", etc.
 -- Try doing: `select 1::"bigint"` - it'll err, using "int8" will work though. There's some parser magic that pg does that's invalidated when quoting.
 -- Not quoting should be fine, we validate the input on Parsers.
-pgFmtSelectItem table (f@(fName, jp), Just cast, alias, _, _) = "CAST (" <> pgFmtField table f <> " AS " <> SQL.sql (encodeUtf8 cast) <> " )" <> SQL.sql (pgFmtAs fName jp alias)
+pgFmtSelectItem table (f@(fName, jp), Just cast, alias) = "CAST (" <> pgFmtField table f <> " AS " <> SQL.sql (encodeUtf8 cast) <> " )" <> SQL.sql (pgFmtAs fName jp alias)

 pgFmtOrderTerm :: QualifiedIdentifier -> OrderTerm -> SQL.Snippet
 pgFmtOrderTerm qi ot =
@@ -227,8 +259,8 @@ pgFmtOrderTerm qi ot =
 pgFmtFilter :: QualifiedIdentifier -> Filter -> SQL.Snippet
 pgFmtFilter table (Filter fld (OpExpr hasNot oper)) = notOp <> " " <> case oper of
   Op op val  -> pgFmtFieldOp op <> " " <> case op of
-     "like"  -> unknownLiteral (T.map star val)
-     "ilike" -> unknownLiteral (T.map star val)
+     OpLike  -> unknownLiteral (T.map star val)
+     OpILike -> unknownLiteral (T.map star val)
     _       -> unknownLiteral val

   -- IS cannot be prepared. `PREPARE boolplan AS SELECT * FROM projects where id IS $1` will give a syntax error.
@@ -249,11 +281,11 @@ pgFmtFilter table (Filter fld (OpExpr hasNot oper)) = notOp <> " " <> case oper
      _    -> "= ANY (" <> unknownLiteral (pgBuildArrayLiteral vals) <> ") "

   Fts op lang val ->
-     pgFmtFieldOp op <> "(" <> ftsLang lang <> unknownLiteral val <> ") "
+     pgFmtFieldFts op <> "(" <> ftsLang lang <> unknownLiteral val <> ") "
 where
   ftsLang = maybe mempty (\l -> unknownLiteral l <> ", ")
-   pgFmtFieldOp op = pgFmtField table fld <> " " <> sqlOperator op
-   sqlOperator o = SQL.sql $ M.lookupDefault "=" o operators
+   pgFmtFieldOp op = pgFmtField table fld <> " " <> SQL.sql (singleValOperator op)
+   pgFmtFieldFts op = pgFmtField table fld <> " " <> SQL.sql (ftsOperator op)
   notOp = if hasNot then "NOT" else mempty
   star c = if c == '*' then '%' else c

@@ -325,6 +357,17 @@ currentSettingF setting =
  -- nullif is used because of https://gist.github.com/steve-chavez/8d7033ea5655096903f3b52f8ed09a15
  "nullif(current_setting('" <> setting <> "', true), '')"

+mutRangeF :: QualifiedIdentifier -> [FieldName] -> (SqlFragment, SqlFragment)
+mutRangeF mainQi rangeId =
+  (
+    BS.intercalate " AND " $ (\col -> pgFmtColumn mainQi col <> " = " <> pgFmtColumn (QualifiedIdentifier mempty "pgrst_affected_rows") col) <$> rangeId
+  , BS.intercalate ", " (pgFmtColumn mainQi <$> rangeId)
+  )
+
+orderF :: QualifiedIdentifier -> [OrderTerm] -> SQL.Snippet
+orderF _ []    = mempty
+orderF qi ordts = "ORDER BY " <> intercalateSnippet ", " (pgFmtOrderTerm qi <$> ordts)
+
 -- Hasql Snippet utilities
 unknownEncoder :: ByteString -> SQL.Snippet
 unknownEncoder = SQL.encoderAndParam (HE.nonNullable HE.unknown)
@@ -335,3 +378,34 @@ unknownLiteral = unknownEncoder . encodeUtf8
 intercalateSnippet :: ByteString -> [SQL.Snippet] -> SQL.Snippet
 intercalateSnippet _ [] = mempty
 intercalateSnippet frag snippets = foldr1 (\a b -> a <> SQL.sql frag <> b) snippets
+
+explainF :: MTPlanFormat -> [MTPlanOption] -> SQL.Snippet -> SQL.Snippet
+explainF fmt opts snip =
+  "EXPLAIN (" <>
+    SQL.sql (BS.intercalate ", " (fmtPlanFmt fmt : (fmtPlanOpt <$> opts))) <>
+  ") " <> snip
+  where
+    fmtPlanOpt :: MTPlanOption -> BS.ByteString
+    fmtPlanOpt PlanAnalyze  = "ANALYZE"
+    fmtPlanOpt PlanVerbose  = "VERBOSE"
+    fmtPlanOpt PlanSettings = "SETTINGS"
+    fmtPlanOpt PlanBuffers  = "BUFFERS"
+    fmtPlanOpt PlanWAL      = "WAL"
+
+    fmtPlanFmt PlanJSON = "FORMAT JSON"
+    fmtPlanFmt PlanText = "FORMAT TEXT"
+
+-- | Do a pg set_config(setting, value, true) call. This is equivalent to a SET LOCAL.
+setConfigLocal :: ByteString -> (ByteString, ByteString) -> SQL.Snippet
+setConfigLocal prefix (k, v) =
+  "set_config(" <> unknownEncoder (prefix <> k) <> ", " <> unknownEncoder v <> ", true)"
+
+-- | Starting from PostgreSQL v14, some characters are not allowed for config names (mostly affecting headers with "-").
+-- | A JSON format string is used to avoid this problem. See https://github.com/PostgREST/postgrest/issues/1857
+setConfigLocalJson :: ByteString -> [(ByteString, ByteString)] -> [SQL.Snippet]
+setConfigLocalJson prefix keyVals = [setConfigLocal mempty (prefix, gucJsonVal keyVals)]
+  where
+    gucJsonVal :: [(ByteString, ByteString)] -> ByteString
+    gucJsonVal = LBS.toStrict . JSON.encode . HM.fromList . arrayByteStringToText
+    arrayByteStringToText :: [(ByteString, ByteString)] -> [(Text,Text)]
+    arrayByteStringToText keyVal = (T.decodeUtf8 *** T.decodeUtf8) <$> keyVal
@@ -6,50 +6,59 @@ This module constructs single SQL statements that can be parametrized and prepar

 - It consumes the SqlQuery types generated by the QueryBuilder module.
 - It generates the body format and some headers of the final HTTP response.
-
-TODO: Currently, createReadStatement is not using prepared statements. See https://github.com/PostgREST/postgrest/issues/718.
 -}
 module PostgREST.Query.Statements
-  ( createWriteStatement
-  , createReadStatement
-  , callProcStatement
-  , createExplainStatement
+  ( prepareWrite
+  , prepareRead
+  , prepareCall
+  , preparePlanRows
+  , ResultSet (..)
  ) where

-import qualified Data.Aeson                        as JSON
 import qualified Data.Aeson.Lens                   as L
 import qualified Data.ByteString.Char8             as BS
-import qualified Data.ByteString.Lazy              as LBS
 import qualified Hasql.Decoders                    as HD
 import qualified Hasql.DynamicStatements.Snippet   as SQL
 import qualified Hasql.DynamicStatements.Statement as SQL
 import qualified Hasql.Statement                   as SQL

-import Control.Lens              ((^?))
-import Data.Maybe                (fromJust)
-import Data.Text.Read            (decimal)
-import Network.HTTP.Types.Status (Status)
+import Control.Lens ((^?))
+import Data.Maybe   (fromJust)

-import PostgREST.Error     (Error (..))
-import PostgREST.GucHeader (GucHeader)
-
-import PostgREST.DbStructure.Identifiers (FieldName)
+import PostgREST.ApiRequest.Preferences
+import PostgREST.MediaType               (MTPlanAttrs (..),
+                                          MTPlanFormat (..),
+                                          MediaType (..),
+                                          getMediaType)
 import PostgREST.Query.SqlFragment
-import PostgREST.Request.Preferences
+import PostgREST.SchemaCache.Identifiers (FieldName)

 import Protolude

-{-| The generic query result format used by API responses. The location header
-    is represented as a list of strings containing variable bindings like
-    @"k1=eq.42"@, or the empty list if there is no location header.
-}
-type ResultsWithCount = (Maybe Int64, Int64, [BS.ByteString], BS.ByteString, Either Error [GucHeader], Either Error (Maybe Status))
+-- | Standard result set format used for all queries
+data ResultSet
+  = RSStandard
+  { rsTableTotal :: Maybe Int64
+  -- ^ count of all the table rows
+  , rsQueryTotal :: Int64
+  -- ^ count of the query rows
+  , rsLocation   :: [(BS.ByteString, BS.ByteString)]
+  -- ^ The Location header(only used for inserts) is represented as a list of strings containing
+  -- variable bindings like @"k1=eq.42"@, or the empty list if there is no location header.
+  , rsBody       :: BS.ByteString
+  -- ^ the aggregated body of the query
+  , rsGucHeaders :: Maybe BS.ByteString
+  -- ^ the HTTP headers to be added to the response
+  , rsGucStatus  :: Maybe Text
+  -- ^ the HTTP status to be added to the response
+  }
+  | RSPlan BS.ByteString -- ^ the plan of the query

-createWriteStatement :: SQL.Snippet -> SQL.Snippet -> Bool -> Bool -> Bool ->
-                        PreferRepresentation -> [Text] -> Bool ->
-                        SQL.Statement () ResultsWithCount
-createWriteStatement selectQuery mutateQuery wantSingle isInsert asCsv rep pKeys =
-  SQL.dynamicallyParameterized snippet decodeStandard
+
+prepareWrite :: SQL.Snippet -> SQL.Snippet -> Bool -> MediaType ->
+                PreferRepresentation -> [Text] -> Bool -> SQL.Statement () ResultSet
+prepareWrite selectQuery mutateQuery isInsert mt rep pKeys =
+  SQL.dynamicallyParameterized (mtSnippet mt snippet) decodeIt
 where
  snippet =
    "WITH " <> SQL.sql sourceCTEName <> " AS (" <> mutateQuery <> ") " <>
@@ -65,7 +74,7 @@ createWriteStatement selectQuery mutateQuery wantSingle isInsert asCsv rep pKeys
    "FROM (" <> selectF <> ") _postgrest_t"

  locF =
-    if isInsert && rep `elem` [Full, HeadersOnly]
+    if isInsert && rep == HeadersOnly
      then BS.unwords [
        "CASE WHEN pg_catalog.count(_postgrest_t) = 1",
          "THEN coalesce(" <> locationF pKeys <> ", " <> noLocationF <> ")",
@@ -74,24 +83,25 @@ createWriteStatement selectQuery mutateQuery wantSingle isInsert asCsv rep pKeys
      else noLocationF

  bodyF
-    | rep `elem` [None, HeadersOnly] = "''"
-    | asCsv = asCsvF
-    | wantSingle = asJsonSingleF False
-    | otherwise = asJsonF False
+    | rep /= Full                       = "''"
+    | getMediaType mt == MTTextCSV      = asCsvF
+    | getMediaType mt == MTGeoJSON      = asGeoJsonF
+    | getMediaType mt == MTSingularJSON = asJsonSingleF False
+    | otherwise                         = asJsonF False

  selectF
    -- prevent using any of the column names in ?select= when no response is returned from the CTE
-    | rep `elem` [None, HeadersOnly] = SQL.sql ("SELECT * FROM " <> sourceCTEName)
-    | otherwise                      = selectQuery
+    | rep /= Full = SQL.sql ("SELECT * FROM " <> sourceCTEName)
+    | otherwise   = selectQuery

-  decodeStandard :: HD.Result ResultsWithCount
-  decodeStandard =
-   fromMaybe (Nothing, 0, [], mempty, Right [], Right Nothing) <$> HD.rowMaybe standardRow
+  decodeIt :: HD.Result ResultSet
+  decodeIt = case mt of
+    MTPlan{} -> planRow
+    _        -> fromMaybe (RSStandard Nothing 0 mempty mempty Nothing Nothing) <$> HD.rowMaybe (standardRow False)

-createReadStatement :: SQL.Snippet -> SQL.Snippet -> Bool -> Bool -> Bool -> Maybe FieldName -> Bool ->
-                       SQL.Statement () ResultsWithCount
-createReadStatement selectQuery countQuery isSingle countTotal asCsv binaryField =
-  SQL.dynamicallyParameterized snippet decodeStandard
+prepareRead :: SQL.Snippet -> SQL.Snippet -> Bool -> MediaType -> Maybe FieldName -> Bool -> SQL.Statement () ResultSet
+prepareRead selectQuery countQuery countTotal mt binaryField =
+  SQL.dynamicallyParameterized (mtSnippet mt snippet) decodeIt
 where
  snippet =
    "WITH " <>
@@ -100,7 +110,6 @@ createReadStatement selectQuery countQuery isSingle countTotal asCsv binaryField
    SQL.sql ("SELECT " <>
      countResultF <> " AS total_result_set, " <>
      "pg_catalog.count(_postgrest_t) AS page_total, " <>
-      noLocationF <> " AS header, " <>
      bodyF <> " AS body, " <>
      responseHeadersF <> " AS response_headers, " <>
      responseStatusF <> " AS response_status " <>
@@ -109,32 +118,23 @@ createReadStatement selectQuery countQuery isSingle countTotal asCsv binaryField
  (countCTEF, countResultF) = countF countQuery countTotal

  bodyF
-    | asCsv = asCsvF
-    | isSingle = asJsonSingleF False
-    | isJust binaryField = asBinaryF $ fromJust binaryField
-    | otherwise = asJsonF False
+    | getMediaType mt == MTTextCSV                       = asCsvF
+    | getMediaType mt == MTSingularJSON                  = asJsonSingleF False
+    | getMediaType mt == MTGeoJSON                       = asGeoJsonF
+    | isJust binaryField && getMediaType mt == MTTextXML = asXmlF $ fromJust binaryField
+    | isJust binaryField                                 = asBinaryF $ fromJust binaryField
+    | otherwise                                          = asJsonF False

-  decodeStandard :: HD.Result ResultsWithCount
-  decodeStandard =
-    HD.singleRow standardRow
+  decodeIt :: HD.Result ResultSet
+  decodeIt = case mt of
+    MTPlan{} -> planRow
+    _        -> HD.singleRow $ standardRow True

-{-| Read and Write api requests use a similar response format which includes
-    various record counts and possible location header. This is the decoder
-    for that common type of query.
-}
-standardRow :: HD.Row ResultsWithCount
-standardRow = (,,,,,) <$> nullableColumn HD.int8 <*> column HD.int8
-                      <*> arrayColumn HD.bytea <*> column HD.bytea
-                      <*> (fromMaybe (Right []) <$> nullableColumn decodeGucHeaders)
-                      <*> (fromMaybe (Right Nothing) <$> nullableColumn decodeGucStatus)
-
-type ProcResults = (Maybe Int64, Int64, ByteString, Either Error [GucHeader], Either Error (Maybe Status))
-
-callProcStatement :: Bool -> Bool -> SQL.Snippet -> SQL.Snippet -> SQL.Snippet -> Bool ->
-                     Bool -> Bool -> Bool -> Maybe FieldName -> Bool ->
-                     SQL.Statement () ProcResults
-callProcStatement returnsScalar returnsSingle callProcQuery selectQuery countQuery countTotal asSingle asCsv multObjects binaryField =
-  SQL.dynamicallyParameterized snippet decodeProc
+prepareCall :: Bool -> Bool -> SQL.Snippet -> SQL.Snippet -> SQL.Snippet -> Bool ->
+               MediaType -> Bool -> Maybe FieldName -> Bool ->
+               SQL.Statement () ResultSet
+prepareCall returnsScalar returnsSingle callProcQuery selectQuery countQuery countTotal mt multObjects binaryField =
+  SQL.dynamicallyParameterized (mtSnippet mt snippet) decodeIt
  where
    snippet =
      "WITH " <> SQL.sql sourceCTEName <> " AS (" <> callProcQuery <> ") " <>
@@ -151,47 +151,49 @@ callProcStatement returnsScalar returnsSingle callProcQuery selectQuery countQue
    (countCTEF, countResultF) = countF countQuery countTotal

    bodyF
-     | asSingle           = asJsonSingleF returnsScalar
-     | asCsv              = asCsvF
-     | isJust binaryField = asBinaryF $ fromJust binaryField
-     | returnsSingle
-       && not multObjects = asJsonSingleF returnsScalar
-     | otherwise          = asJsonF returnsScalar
+     | getMediaType mt == MTSingularJSON                  = asJsonSingleF returnsScalar
+     | getMediaType mt == MTTextCSV                       = asCsvF
+     | getMediaType mt == MTGeoJSON                       = asGeoJsonF
+     | isJust binaryField && getMediaType mt == MTTextXML = asXmlF $ fromJust binaryField
+     | isJust binaryField                                 = asBinaryF $ fromJust binaryField
+     | returnsSingle && not multObjects                   = asJsonSingleF returnsScalar
+     | otherwise                                          = asJsonF returnsScalar

-    decodeProc :: HD.Result ProcResults
-    decodeProc =
-      fromMaybe (Just 0, 0, mempty, defGucHeaders, defGucStatus) <$> HD.rowMaybe procRow
-      where
-        defGucHeaders = Right []
-        defGucStatus  = Right Nothing
-        procRow = (,,,,) <$> nullableColumn HD.int8 <*> column HD.int8
-                         <*> column HD.bytea
-                         <*> (fromMaybe defGucHeaders <$> nullableColumn decodeGucHeaders)
-                         <*> (fromMaybe defGucStatus <$> nullableColumn decodeGucStatus)
+    decodeIt :: HD.Result ResultSet
+    decodeIt = case mt of
+      MTPlan{} -> planRow
+      _        -> fromMaybe (RSStandard (Just 0) 0 mempty mempty Nothing Nothing) <$> HD.rowMaybe (standardRow True)

-createExplainStatement :: SQL.Snippet -> Bool -> SQL.Statement () (Maybe Int64)
-createExplainStatement countQuery =
-  SQL.dynamicallyParameterized snippet decodeExplain
+preparePlanRows :: SQL.Snippet -> Bool -> SQL.Statement () (Maybe Int64)
+preparePlanRows countQuery =
+  SQL.dynamicallyParameterized snippet decodeIt
  where
-    snippet = "EXPLAIN (FORMAT JSON) " <> countQuery
-    -- |
-    -- An `EXPLAIN (FORMAT JSON) select * from items;` output looks like this:
-    -- [{
-    --   "Plan": {
-    --     "Node Type": "Seq Scan", "Parallel Aware": false, "Relation Name": "items",
-    --     "Alias": "items", "Startup Cost": 0.00, "Total Cost": 32.60,
-    --     "Plan Rows": 2260,"Plan Width": 8} }]
-    -- We only obtain the Plan Rows here.
-    decodeExplain :: HD.Result (Maybe Int64)
-    decodeExplain =
+    snippet = explainF PlanJSON mempty countQuery
+    decodeIt :: HD.Result (Maybe Int64)
+    decodeIt =
      let row = HD.singleRow $ column HD.bytea in
      (^? L.nth 0 . L.key "Plan" .  L.key "Plan Rows" . L._Integral) <$> row

-decodeGucHeaders :: HD.Value (Either Error [GucHeader])
-decodeGucHeaders = first (const GucHeadersError) . JSON.eitherDecode . LBS.fromStrict <$> HD.bytea
+standardRow :: Bool -> HD.Row ResultSet
+standardRow noLocation =
+  RSStandard <$> nullableColumn HD.int8 <*> column HD.int8
+             <*> (if noLocation then pure mempty else fmap splitKeyValue <$> arrayColumn HD.bytea) <*> column HD.bytea
+             <*> nullableColumn HD.bytea
+             <*> nullableColumn HD.text
+  where
+    splitKeyValue :: ByteString -> (ByteString, ByteString)
+    splitKeyValue kv =
+      let (k, v) = BS.break (== '=') kv in
+      (k, BS.tail v)

-decodeGucStatus :: HD.Value (Either Error (Maybe Status))
-decodeGucStatus = first (const GucStatusError) . fmap (Just . toEnum . fst) . decimal <$> HD.text
+mtSnippet :: MediaType -> SQL.Snippet -> SQL.Snippet
+mtSnippet mediaType snippet = case mediaType of
+  MTPlan (MTPlanAttrs _ fmt opts) -> explainF fmt opts snippet
+  _                               -> snippet
+
+-- | We use rowList because when doing EXPLAIN (FORMAT TEXT), the result comes as many rows. FORMAT JSON comes as one.
+planRow :: HD.Result ResultSet
+planRow = RSPlan . BS.unlines <$> HD.rowList (column HD.bytea)

 column :: HD.Value a -> HD.Row a
 column = HD.column . HD.nonNullable
@@ -10,6 +10,9 @@ module PostgREST.RangeQuery (
 , restrictRange
 , rangeGeq
 , allRange
+, limitZeroRange
+, hasLimitZero
+, convertToLimitZeroRange
 , NonnegRange
 , rangeStatusHeader
 , contentRangeH
@@ -34,13 +37,14 @@ rangeParse :: BS.ByteString -> NonnegRange
 rangeParse range = do
  let rangeRegex = "^([0-9]+)-([0-9]*)$" :: BS.ByteString

-  case listToMaybe (range =~ rangeRegex :: [[BS.ByteString]]) of
-    Just parsedRange ->
-      let [_, mLower, mUpper] = readMaybe . BS.unpack <$> parsedRange
-          lower         = maybe emptyRange rangeGeq mLower
-          upper         = maybe allRange rangeLeq mUpper in
+  case range =~ rangeRegex :: [[BS.ByteString]] of
+    [[_, l, u]] ->
+      let lower  = maybe emptyRange rangeGeq (readInteger l)
+          upper  = maybe allRange rangeLeq (readInteger u) in
      rangeIntersection lower upper
-    Nothing -> allRange
+    _ -> allRange
+  where
+    readInteger = readMaybe . BS.unpack

 rangeRequested :: RequestHeaders -> NonnegRange
 rangeRequested headers = maybe allRange rangeParse $ lookup hRange headers
@@ -74,6 +78,21 @@ rangeLeq :: Integer -> NonnegRange
 rangeLeq n =
  Range BoundaryBelowAll (BoundaryAbove n)

+-- Special case to allow limit 0 queries
+-- https://github.com/PostgREST/postgrest/issues/1121
+-- 0 <= x <= -1
+limitZeroRange :: Range Integer
+limitZeroRange = Range (BoundaryBelow 0) (BoundaryAbove (-1))
+
+hasLimitZero :: Range Integer -> Bool
+hasLimitZero r = rangeUpper r == rangeUpper limitZeroRange
+
+-- Used to convert a range into a special limitZeroRange if it has a
+-- limit=0 in order to bypass validations for empty ranges.
+convertToLimitZeroRange :: Range Integer -> Range Integer -> Range Integer
+convertToLimitZeroRange range fallbackRange =
+  if hasLimitZero range then limitZeroRange else fallbackRange
+
 rangeStatusHeader :: NonnegRange -> Int64 -> Maybe Int64 -> (Status, Header)
 rangeStatusHeader topLevelRange queryTotal tableTotal =
  let lower = rangeOffset topLevelRange
@@ -1,518 +0,0 @@
-{-|
-Module      : PostgREST.Request.ApiRequest
-Description : PostgREST functions to translate HTTP request to a domain type called ApiRequest.
-}
-{-# LANGUAGE LambdaCase      #-}
-{-# LANGUAGE NamedFieldPuns  #-}
-{-# LANGUAGE RecordWildCards #-}
-
-module PostgREST.Request.ApiRequest
-  ( ApiRequest(..)
-  , InvokeMethod(..)
-  , ContentType(..)
-  , Action(..)
-  , Target(..)
-  , Payload(..)
-  , userApiRequest
-  ) where
-
-import qualified Data.Aeson            as JSON
-import qualified Data.ByteString.Char8 as BS
-import qualified Data.ByteString.Lazy  as LBS
-import qualified Data.CaseInsensitive  as CI
-import qualified Data.Csv              as CSV
-import qualified Data.HashMap.Strict   as M
-import qualified Data.List             as L
-import qualified Data.List.NonEmpty    as NonEmptyList
-import qualified Data.Set              as S
-import qualified Data.Text             as T
-import qualified Data.Text.Encoding    as T
-import qualified Data.Vector           as V
-
-import Control.Arrow             ((***))
-import Data.Aeson.Types          (emptyArray, emptyObject)
-import Data.List                 (last, lookup, partition, union)
-import Data.Maybe                (fromJust)
-import Data.Ranged.Boundaries    (Boundary (..))
-import Data.Ranged.Ranges        (Range (..), emptyRange,
-                                  rangeIntersection)
-import Network.HTTP.Base         (urlEncodeVars)
-import Network.HTTP.Types.Header (hAuthorization, hCookie)
-import Network.HTTP.Types.URI    (parseQueryReplacePlus,
-                                  parseSimpleQuery)
-import Network.Wai               (Request (..))
-import Network.Wai.Parse         (parseHttpAccept)
-import Web.Cookie                (parseCookies)
-
-import PostgREST.Config                  (AppConfig (..),
-                                          OpenAPIMode (..))
-import PostgREST.ContentType             (ContentType (..))
-import PostgREST.DbStructure             (DbStructure (..))
-import PostgREST.DbStructure.Identifiers (FieldName,
-                                          QualifiedIdentifier (..),
-                                          Schema)
-import PostgREST.DbStructure.Proc        (ProcDescription (..),
-                                          ProcParam (..), ProcsMap)
-import PostgREST.Error                   (ApiRequestError (..))
-import PostgREST.Query.SqlFragment       (ftsOperators, operators)
-import PostgREST.RangeQuery              (NonnegRange, allRange,
-                                          rangeGeq, rangeLimit,
-                                          rangeOffset, rangeRequested,
-                                          restrictRange)
-import PostgREST.Request.Parsers         (pRequestColumns)
-import PostgREST.Request.Preferences     (PreferCount (..),
-                                          PreferParameters (..),
-                                          PreferRepresentation (..),
-                                          PreferResolution (..),
-                                          PreferTransaction (..))
-
-import qualified PostgREST.ContentType         as ContentType
-import qualified PostgREST.Request.Preferences as Preferences
-
-import Protolude
-
-
-type RequestBody = LBS.ByteString
-
-data Payload
-  = ProcessedJSON -- ^ Cached attributes of a JSON payload
-      { payRaw  :: LBS.ByteString
-      -- ^ This is the raw ByteString that comes from the request body.  We
-      -- cache this instead of an Aeson Value because it was detected that for
-      -- large payloads the encoding had high memory usage, see
-      -- https://github.com/PostgREST/postgrest/pull/1005 for more details
-      , payKeys :: S.Set Text
-      -- ^ Keys of the object or if it's an array these keys are guaranteed to
-      -- be the same across all its objects
-      }
-  | RawJSON { payRaw  :: LBS.ByteString }
-  | RawPay  { payRaw  :: LBS.ByteString }
-
-data InvokeMethod = InvHead | InvGet | InvPost deriving Eq
-- | Types of things a user wants to do to tables/views/procs
-data Action = ActionCreate       | ActionRead{isHead :: Bool}
-            | ActionUpdate       | ActionDelete
-            | ActionSingleUpsert | ActionInvoke InvokeMethod
-            | ActionInfo         | ActionInspect{isHead :: Bool}
-            deriving Eq
-- | The path info that will be mapped to a target (used to handle validations and errors before defining the Target)
-data Path
-  = PathInfo
-      { pSchema        :: Schema,
-        pName          :: Text,
-        pHasRpc        :: Bool,
-        pIsDefaultSpec :: Bool,
-        pIsRootSpec    :: Bool
-      }
-  | PathUnknown
-- | The target db object of a user action
-data Target = TargetIdent QualifiedIdentifier
-            | TargetProc{tProc :: ProcDescription, tpIsRootSpec :: Bool}
-            | TargetDefaultSpec{tdsSchema :: Schema} -- The default spec offered at root "/"
-            | TargetUnknown
-
-- | RPC query param value `/rpc/func?v=<value>`, used for VARIADIC functions on form-urlencoded POST and GETs
-- | It can be fixed `?v=1` or repeated `?v=1&v=2&v=3.
-data RpcParamValue = Fixed Text | Variadic [Text]
-instance JSON.ToJSON RpcParamValue where
-  toJSON (Fixed    v) = JSON.toJSON v
-  toJSON (Variadic v) = JSON.toJSON v
-
-toRpcParamValue :: ProcDescription -> (Text, Text) -> (Text, RpcParamValue)
-toRpcParamValue proc (k, v) | prmIsVariadic k = (k, Variadic [v])
-                            | otherwise       = (k, Fixed v)
-  where
-    prmIsVariadic prm = isJust $ find (\ProcParam{ppName, ppVar} -> ppName == prm && ppVar) $ pdParams proc
-
-- | Convert rpc params `/rpc/func?a=val1&b=val2` to json `{"a": "val1", "b": "val2"}
-jsonRpcParams :: ProcDescription -> [(Text, Text)] -> Payload
-jsonRpcParams proc prms =
-  if not $ pdHasVariadic proc then -- if proc has no variadic param, save steps and directly convert to json
-    ProcessedJSON (JSON.encode $ M.fromList $ second JSON.toJSON <$> prms) (S.fromList $ fst <$> prms)
-  else
-    let paramsMap = M.fromListWith mergeParams $ toRpcParamValue proc <$> prms in
-    ProcessedJSON (JSON.encode paramsMap) (S.fromList $ M.keys paramsMap)
-  where
-    mergeParams :: RpcParamValue -> RpcParamValue -> RpcParamValue
-    mergeParams (Variadic a) (Variadic b) = Variadic $ b ++ a
-    mergeParams v _                       = v -- repeated params for non-variadic parameters are not merged
-
-targetToJsonRpcParams :: Maybe Target -> [(Text, Text)] -> Maybe Payload
-targetToJsonRpcParams target params =
-  case target of
-    Just TargetProc{tProc} -> Just $ jsonRpcParams tProc params
-    _                      -> Nothing
-
-{-|
-  Describes what the user wants to do. This data type is a
-  translation of the raw elements of an HTTP request into domain
-  specific language.  There is no guarantee that the intent is
-  sensible, it is up to a later stage of processing to determine
-  if it is an action we are able to perform.
-}
-data ApiRequest = ApiRequest {
-    iAction               :: Action                           -- ^ Similar but not identical to HTTP verb, e.g. Create/Invoke both POST
-  , iRange                :: M.HashMap Text NonnegRange -- ^ Requested range of rows within response
-  , iTopLevelRange        :: NonnegRange                      -- ^ Requested range of rows from the top level
-  , iTarget               :: Target                           -- ^ The target, be it calling a proc or accessing a table
-  , iPayload              :: Maybe Payload                    -- ^ Data sent by client and used for mutation actions
-  , iPreferRepresentation :: PreferRepresentation             -- ^ If client wants created items echoed back
-  , iPreferParameters     :: Maybe PreferParameters           -- ^ How to pass parameters to a stored procedure
-  , iPreferCount          :: Maybe PreferCount                -- ^ Whether the client wants a result count
-  , iPreferResolution     :: Maybe PreferResolution           -- ^ Whether the client wants to UPSERT or ignore records on PK conflict
-  , iPreferTransaction    :: Maybe PreferTransaction          -- ^ Whether the clients wants to commit or rollback the transaction
-  , iFilters              :: [(Text, Text)]                   -- ^ Filters on the result ("id", "eq.10")
-  , iLogic                :: [(Text, Text)]                   -- ^ &and and &or parameters used for complex boolean logic
-  , iSelect               :: Maybe Text                       -- ^ &select parameter used to shape the response
-  , iOnConflict           :: Maybe Text                       -- ^ &on_conflict parameter used to upsert on specific unique keys
-  , iColumns              :: S.Set FieldName                  -- ^ parsed colums from &columns parameter and payload
-  , iOrder                :: [(Text, Text)]                   -- ^ &order parameters for each level
-  , iCanonicalQS          :: ByteString                       -- ^ Alphabetized (canonical) request query string for response URLs
-  , iJWT                  :: Text                             -- ^ JSON Web Token
-  , iHeaders              :: [(ByteString, ByteString)]       -- ^ HTTP request headers
-  , iCookies              :: [(ByteString, ByteString)]       -- ^ Request Cookies
-  , iPath                 :: ByteString                       -- ^ Raw request path
-  , iMethod               :: ByteString                       -- ^ Raw request method
-  , iProfile              :: Maybe Schema                     -- ^ The request profile for enabling use of multiple schemas. Follows the spec in hhttps://www.w3.org/TR/dx-prof-conneg/ttps://www.w3.org/TR/dx-prof-conneg/.
-  , iSchema               :: Schema                           -- ^ The request schema. Can vary depending on iProfile.
-  , iAcceptContentType    :: ContentType
-  }
-
-- | Examines HTTP request and translates it into user intent.
-userApiRequest :: AppConfig -> DbStructure -> Request -> RequestBody -> Either ApiRequestError ApiRequest
-userApiRequest conf@AppConfig{..} dbStructure req reqBody
-  | isJust profile && fromJust profile `notElem` configDbSchemas = Left $ UnacceptableSchema $ toList configDbSchemas
-  | isTargetingProc && method `notElem` ["HEAD", "GET", "POST"] = Left ActionInappropriate
-  | topLevelRange == emptyRange = Left InvalidRange
-  | shouldParsePayload && isLeft payload = either (Left . InvalidBody) witness payload
-  | isLeft parsedColumns = either Left witness parsedColumns
-  | otherwise = do
-     acceptContentType <- findAcceptContentType conf action path accepts
-     checkedTarget <- target
-     return ApiRequest {
-      iAction = action
-      , iTarget = checkedTarget
-      , iRange = ranges
-      , iTopLevelRange = topLevelRange
-      , iPayload = relevantPayload
-      , iPreferRepresentation = fromMaybe None preferRepresentation
-      , iPreferParameters = preferParameters
-      , iPreferCount = preferCount
-      , iPreferResolution = preferResolution
-      , iPreferTransaction = preferTransaction
-      , iFilters = filters
-      , iLogic = [(toS k, toS $ fromJust v) | (k,v) <- qParams, isJust v, endingIn ["and", "or"] k ]
-      , iSelect = toS <$> join (lookup "select" qParams)
-      , iOnConflict = toS <$> join (lookup "on_conflict" qParams)
-      , iColumns = payloadColumns
-      , iOrder = [(toS k, toS $ fromJust v) | (k,v) <- qParams, isJust v, endingIn ["order"] k ]
-      , iCanonicalQS = BS.pack $ urlEncodeVars
-        . L.sortOn fst
-        . map (join (***) BS.unpack . second (fromMaybe mempty))
-        $ qString
-      , iJWT = tokenStr
-      , iHeaders = [ (CI.foldedCase k, v) | (k,v) <- hdrs, k /= hCookie]
-      , iCookies = maybe [] parseCookies $ lookupHeader "Cookie"
-      , iPath = rawPathInfo req
-      , iMethod = method
-      , iProfile = profile
-      , iSchema = schema
-      , iAcceptContentType = acceptContentType
-      }
- where
-  accepts = maybe [CTAny] (map ContentType.decodeContentType . parseHttpAccept) $ lookupHeader "accept"
-  -- queryString with '+' converted to ' '(space)
-  qString = parseQueryReplacePlus True $ rawQueryString req
-  -- rpcQParams = Rpc query params e.g. /rpc/name?param1=val1, similar to filter but with no operator(eq, lt..)
-  (filters, rpcQParams) =
-    case action of
-      ActionInvoke InvGet  -> partitionFlts
-      ActionInvoke InvHead -> partitionFlts
-      _                    -> (flts, [])
-  partitionFlts = partition (liftM2 (||) (isEmbedPath . fst) (hasOperator . snd)) flts
-  flts =
-    [ (toS k, toS $ fromJust v) |
-      (k,v) <- qParams, isJust v,
-      k `notElem` ["select", "columns"],
-      not (endingIn ["order", "limit", "offset", "and", "or"] k) ]
-  hasOperator val = any (`T.isPrefixOf` val) $
-                      ((<> ".") <$> "not":M.keys operators) ++
-                      ((<> "(") <$> M.keys ftsOperators)
-  isEmbedPath = T.isInfixOf "."
-  isTargetingProc = case path of
-    PathInfo{pHasRpc, pIsRootSpec} -> pHasRpc || pIsRootSpec
-    _                              -> False
-  isTargetingDefaultSpec = case path of
-    PathInfo{pIsDefaultSpec=True} -> True
-    _                             -> False
-  contentType = maybe CTApplicationJSON ContentType.decodeContentType $ lookupHeader "content-type"
-  columns
-    | action `elem` [ActionCreate, ActionUpdate, ActionInvoke InvPost] = toS <$> join (lookup "columns" qParams)
-    | otherwise = Nothing
-  parsedColumns = pRequestColumns columns
-  payloadColumns =
-    case (contentType, action) of
-      (_, ActionInvoke InvGet)  -> S.fromList $ fst <$> rpcQParams
-      (_, ActionInvoke InvHead) -> S.fromList $ fst <$> rpcQParams
-      (CTUrlEncoded, _)         -> S.fromList $ map (T.decodeUtf8 . fst) $ parseSimpleQuery $ LBS.toStrict reqBody
-      _ -> case (relevantPayload, fromRight Nothing parsedColumns) of
-        (Just ProcessedJSON{payKeys}, _) -> payKeys
-        (Just RawJSON{}, Just cls)       -> cls
-        _                                -> S.empty
-  payload :: Either ByteString Payload
-  payload = case contentType of
-    CTApplicationJSON ->
-      if isJust columns
-        then Right $ RawJSON reqBody
-        else note "All object keys must match" . payloadAttributes reqBody
-               =<< if LBS.null reqBody && isTargetingProc
-                     then Right emptyObject
-                     else first BS.pack $ JSON.eitherDecode reqBody
-    CTTextCSV -> do
-      json <- csvToJson <$> first BS.pack (CSV.decodeByName reqBody)
-      note "All lines must have same number of fields" $ payloadAttributes (JSON.encode json) json
-    CTUrlEncoded ->
-      let paramsMap = M.fromList $ (T.decodeUtf8 *** JSON.String . T.decodeUtf8) <$> parseSimpleQuery (LBS.toStrict reqBody) in
-      Right $ ProcessedJSON (JSON.encode paramsMap) $ S.fromList (M.keys paramsMap)
-    ct ->
-      if isTargetingProc && ct `elem` [CTTextPlain, CTOctetStream]
-        then Right $ RawPay reqBody
-        else Left $ "Content-Type not acceptable: " <> ContentType.toMime ct
-  topLevelRange = fromMaybe allRange $ M.lookup "limit" ranges -- if no limit is specified, get all the request rows
-  action =
-    case method of
-      -- The HEAD method is identical to GET except that the server MUST NOT return a message-body in the response
-      -- From https://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html#sec9.4
-      "HEAD"     | isTargetingDefaultSpec -> ActionInspect{isHead=True}
-                 | isTargetingProc        -> ActionInvoke InvHead
-                 | otherwise              -> ActionRead{isHead=True}
-      "GET"      | isTargetingDefaultSpec -> ActionInspect{isHead=False}
-                 | isTargetingProc        -> ActionInvoke InvGet
-                 | otherwise              -> ActionRead{isHead=False}
-      "POST"    -> if isTargetingProc
-                    then ActionInvoke InvPost
-                    else ActionCreate
-      "PATCH"   -> ActionUpdate
-      "PUT"     -> ActionSingleUpsert
-      "DELETE"  -> ActionDelete
-      "OPTIONS" -> ActionInfo
-      _         -> ActionInspect{isHead=False}
-
-  defaultSchema = NonEmptyList.head configDbSchemas
-  profile
-    | length configDbSchemas <= 1 -- only enable content negotiation by profile when there are multiple schemas specified in the config
-      = Nothing
-    | otherwise = case action of
-        -- POST/PATCH/PUT/DELETE don't use the same header as per the spec
-        ActionCreate         -> contentProfile
-        ActionUpdate         -> contentProfile
-        ActionSingleUpsert   -> contentProfile
-        ActionDelete         -> contentProfile
-        ActionInvoke InvPost -> contentProfile
-        _                    -> acceptProfile
-    where
-      contentProfile = Just $ maybe defaultSchema T.decodeUtf8 $ lookupHeader "Content-Profile"
-      acceptProfile = Just $ maybe defaultSchema T.decodeUtf8 $ lookupHeader "Accept-Profile"
-  schema = fromMaybe defaultSchema profile
-  target =
-    let
-      callFindProc procSch procNam = findProc
-        (QualifiedIdentifier procSch procNam) payloadColumns (preferParameters == Just SingleObject) (dbProcs dbStructure)
-        contentType (action == ActionInvoke InvPost)
-    in
-    case path of
-      PathInfo{pSchema, pName, pHasRpc, pIsRootSpec, pIsDefaultSpec}
-        | pHasRpc || pIsRootSpec -> (`TargetProc` pIsRootSpec) <$> callFindProc pSchema pName
-        | pIsDefaultSpec         -> Right $ TargetDefaultSpec pSchema
-        | otherwise              -> Right $ TargetIdent $ QualifiedIdentifier pSchema pName
-      PathUnknown -> Right TargetUnknown
-
-  shouldParsePayload = case (contentType, action) of
-    (CTUrlEncoded, ActionInvoke InvPost) -> False
-    (_, act)                             -> act `elem` [ActionCreate, ActionUpdate, ActionSingleUpsert, ActionInvoke InvPost]
-  relevantPayload = case (contentType, action) of
-    -- Though ActionInvoke GET/HEAD doesn't really have a payload, we use the payload variable as a way
-    -- to store the query string arguments to the function.
-    (_, ActionInvoke InvGet)             -> targetToJsonRpcParams (rightToMaybe target) rpcQParams
-    (_, ActionInvoke InvHead)            -> targetToJsonRpcParams (rightToMaybe target) rpcQParams
-    (CTUrlEncoded, ActionInvoke InvPost) -> targetToJsonRpcParams (rightToMaybe target) $ (T.decodeUtf8 *** T.decodeUtf8) <$> parseSimpleQuery (LBS.toStrict reqBody)
-    _ | shouldParsePayload               -> rightToMaybe payload
-      | otherwise                        -> Nothing
-  path =
-    case pathInfo req of
-      []             -> case configDbRootSpec of
-                          Just (QualifiedIdentifier pSch pName)     -> PathInfo (if pSch == mempty then schema else pSch) pName False False True
-                          Nothing | configOpenApiMode == OADisabled -> PathUnknown
-                                  | otherwise                       -> PathInfo schema "" False True False
-      [table]        -> PathInfo schema table False False False
-      ["rpc", pName] -> PathInfo schema pName True False False
-      _              -> PathUnknown
-  method          = requestMethod req
-  hdrs            = requestHeaders req
-  qParams         = [(T.decodeUtf8 k, T.decodeUtf8 <$> v)|(k,v) <- qString]
-  lookupHeader    = flip lookup hdrs
-  Preferences.Preferences{..} = Preferences.fromHeaders hdrs
-  auth = fromMaybe "" $ lookupHeader hAuthorization
-  tokenStr = case T.split (== ' ') (T.decodeUtf8 auth) of
-    ("Bearer" : t : _) -> t
-    ("bearer" : t : _) -> t
-    _                  -> ""
-  endingIn:: [Text] -> Text -> Bool
-  endingIn xx key = lastWord `elem` xx
-    where lastWord = last $ T.split (=='.') key
-
-  headerRange = rangeRequested hdrs
-  replaceLast x s = T.intercalate "." $ L.init (T.split (=='.') s) ++ [x]
-  limitParams :: M.HashMap Text NonnegRange
-  limitParams  = M.fromList [(toS (replaceLast "limit" k), restrictRange (readMaybe . toS =<< v) allRange) | (k,v) <- qParams, isJust v, endingIn ["limit"] k]
-  offsetParams :: M.HashMap Text NonnegRange
-  offsetParams = M.fromList [(toS (replaceLast "limit" k), maybe allRange rangeGeq (readMaybe . toS =<< v)) | (k,v) <- qParams, isJust v, endingIn ["offset"] k]
-
-  urlRange = M.unionWith f limitParams offsetParams
-    where
-      f rl ro = Range (BoundaryBelow o) (BoundaryAbove $ o + l - 1)
-        where
-          l = fromMaybe 0 $ rangeLimit rl
-          o = rangeOffset ro
-  ranges = M.insert "limit" (rangeIntersection headerRange (fromMaybe allRange (M.lookup "limit" urlRange))) urlRange
-
-{-|
-  Find the best match from a list of content types accepted by the
-  client in order of decreasing preference and a list of types
-  producible by the server.  If there is no match but the client
-  accepts */* then return the top server pick.
-}
-mutuallyAgreeable :: [ContentType] -> [ContentType] -> Maybe ContentType
-mutuallyAgreeable sProduces cAccepts =
-  let exact = listToMaybe $ L.intersect cAccepts sProduces in
-  if isNothing exact && CTAny `elem` cAccepts
-     then listToMaybe sProduces
-     else exact
-
-type CsvData = V.Vector (M.HashMap Text LBS.ByteString)
-
-{-|
-  Converts CSV like
-  a,b
-  1,hi
-  2,bye
-
-  into a JSON array like
-  [ {"a": "1", "b": "hi"}, {"a": 2, "b": "bye"} ]
-
-  The reason for its odd signature is so that it can compose
-  directly with CSV.decodeByName
-}
-csvToJson :: (CSV.Header, CsvData) -> JSON.Value
-csvToJson (_, vals) =
-  JSON.Array $ V.map rowToJsonObj vals
- where
-  rowToJsonObj = JSON.Object .
-    M.map (\str ->
-        if str == "NULL"
-          then JSON.Null
-          else JSON.String . T.decodeUtf8 $ LBS.toStrict str
-      )
-
-payloadAttributes :: RequestBody -> JSON.Value -> Maybe Payload
-payloadAttributes raw json =
-  -- Test that Array contains only Objects having the same keys
-  case json of
-    JSON.Array arr ->
-      case arr V.!? 0 of
-        Just (JSON.Object o) ->
-          let canonicalKeys = S.fromList $ M.keys o
-              areKeysUniform = all (\case
-                JSON.Object x -> S.fromList (M.keys x) == canonicalKeys
-                _ -> False) arr in
-          if areKeysUniform
-            then Just $ ProcessedJSON raw canonicalKeys
-            else Nothing
-        Just _ -> Nothing
-        Nothing -> Just emptyPJArray
-
-    JSON.Object o -> Just $ ProcessedJSON raw (S.fromList $ M.keys o)
-
-    -- truncate everything else to an empty array.
-    _ -> Just emptyPJArray
-  where
-    emptyPJArray = ProcessedJSON (JSON.encode emptyArray) S.empty
-
-findAcceptContentType :: AppConfig -> Action -> Path -> [ContentType] -> Either ApiRequestError ContentType
-findAcceptContentType conf action path accepts =
-  case mutuallyAgreeable (requestContentTypes conf action path) accepts of
-    Just ct ->
-      Right ct
-    Nothing ->
-      Left . ContentTypeError $ map ContentType.toMime accepts
-
-requestContentTypes :: AppConfig -> Action -> Path -> [ContentType]
-requestContentTypes conf action path =
-  case action of
-    ActionRead _    -> defaultContentTypes ++ rawContentTypes conf
-    ActionInvoke _  -> invokeContentTypes
-    ActionInspect _ -> [CTOpenAPI, CTApplicationJSON]
-    ActionInfo      -> [CTTextCSV]
-    _               -> defaultContentTypes
-  where
-    invokeContentTypes =
-      defaultContentTypes
-        ++ rawContentTypes conf
-        ++ [CTOpenAPI | pIsRootSpec path]
-    defaultContentTypes =
-      [CTApplicationJSON, CTSingularJSON, CTTextCSV]
-
-rawContentTypes :: AppConfig -> [ContentType]
-rawContentTypes AppConfig{..} =
-  (ContentType.decodeContentType <$> configRawMediaTypes) `union` [CTOctetStream, CTTextPlain]
-
-{-|
-  Search a pg proc by matching name and arguments keys to parameters. Since a function can be overloaded,
-  the name is not enough to find it. An overloaded function can have a different volatility or even a different return type.
-}
-findProc :: QualifiedIdentifier -> S.Set Text -> Bool -> ProcsMap -> ContentType -> Bool -> Either ApiRequestError ProcDescription
-findProc qi argumentsKeys paramsAsSingleObject allProcs contentType isInvPost =
-  case matchProc of
-    ([], [])     -> Left $ NoRpc (qiSchema qi) (qiName qi) (S.toList argumentsKeys) paramsAsSingleObject contentType isInvPost
-    -- If there are no functions with named arguments, fallback to the single unnamed argument function
-    ([], [proc]) -> Right proc
-    ([], procs)  -> Left $ AmbiguousRpc (toList procs)
-    -- Matches the functions with named arguments
-    ([proc], _)  -> Right proc
-    (procs, _)   -> Left $ AmbiguousRpc (toList procs)
-  where
-    matchProc = overloadedProcPartition $ M.lookupDefault mempty qi allProcs -- first find the proc by name
-    -- The partition obtained has the form (overloadedProcs,fallbackProcs)
-    -- where fallbackProcs are functions with a single unnamed parameter
-    overloadedProcPartition procs = foldr select ([],[]) procs
-    select proc ~(ts,fs)
-      | matchesParams proc         = (proc:ts,fs)
-      | hasSingleUnnamedParam proc = (ts,proc:fs)
-      | otherwise                  = (ts,fs)
-    -- If the function is called with post and has a single unnamed parameter
-    -- it can be called depending on content type and the parameter type
-    hasSingleUnnamedParam proc = isInvPost && case pdParams proc of
-      [ProcParam "" ppType _ _]
-        | contentType == CTApplicationJSON -> ppType `elem` ["json", "jsonb"]
-        | contentType == CTTextPlain       -> ppType == "text"
-        | contentType == CTOctetStream     -> ppType == "bytea"
-        | otherwise                        -> False
-      _ -> False
-    matchesParams proc =
-      let params = pdParams proc in
-      -- exceptional case for Prefer: params=single-object
-      if paramsAsSingleObject
-        then length params == 1 && (ppType <$> headMay params) `elem` [Just "json", Just "jsonb"]
-      -- If the function has no parameters, the arguments keys must be empty as well
-      else if null params
-        then null argumentsKeys && contentType `notElem` [CTTextPlain, CTOctetStream]
-      -- A function has optional and required parameters. Optional parameters have a default value and
-      -- don't require arguments for the function to be executed, required parameters must have an argument present.
-      else case L.partition ppReq params of
-      -- If the function only has required parameters, the arguments keys must match those parameters
-        (reqParams, [])        -> argumentsKeys == S.fromList (ppName <$> reqParams)
-      -- If the function only has optional parameters, the arguments keys can match none or any of them(a subset)
-        ([], optParams)        -> argumentsKeys `S.isSubsetOf` S.fromList (ppName <$> optParams)
-      -- If the function has required and optional parameters, the arguments keys have to match the required parameters
-      -- and can match any or none of the default parameters.
-        (reqParams, optParams) -> argumentsKeys `S.difference` S.fromList (ppName <$> optParams) == S.fromList (ppName <$> reqParams)
@@ -1,397 +0,0 @@
-{-|
-Module      : PostgREST.Request.DbRequestBuilder
-Description : PostgREST database request builder
-
-This module is in charge of building an intermediate
-representation(ReadRequest, MutateRequest) between the HTTP request and the
-final resulting SQL query.
-
-A query tree is built in case of resource embedding. By inferring the
-relationship between tables, join conditions are added for every embedded
-resource.
-}
-{-# LANGUAGE DuplicateRecordFields #-}
-{-# LANGUAGE LambdaCase            #-}
-{-# LANGUAGE NamedFieldPuns        #-}
-{-# LANGUAGE RecordWildCards       #-}
-
-module PostgREST.Request.DbRequestBuilder
-  ( readRequest
-  , mutateRequest
-  , callRequest
-  ) where
-
-import qualified Data.HashMap.Strict as M
-import qualified Data.Set            as S
-
-import Control.Arrow           ((***))
-import Data.Either.Combinators (mapLeft)
-import Data.List               (delete)
-import Data.Text               (isInfixOf)
-import Data.Tree               (Tree (..))
-
-import PostgREST.DbStructure.Identifiers  (FieldName,
-                                           QualifiedIdentifier (..),
-                                           Schema, TableName)
-import PostgREST.DbStructure.Proc         (ProcDescription (..),
-                                           ProcParam (..),
-                                           procReturnsScalar)
-import PostgREST.DbStructure.Relationship (Cardinality (..),
-                                           Junction (..),
-                                           Relationship (..))
-import PostgREST.DbStructure.Table        (Column (..), Table (..),
-                                           tableQi)
-import PostgREST.Error                    (ApiRequestError (..),
-                                           Error (..))
-import PostgREST.Query.SqlFragment        (sourceCTEName)
-import PostgREST.RangeQuery               (NonnegRange, allRange,
-                                           restrictRange)
-import PostgREST.Request.ApiRequest       (Action (..),
-                                           ApiRequest (..),
-                                           Payload (..))
-
-import PostgREST.Request.Parsers
-import PostgREST.Request.Preferences
-import PostgREST.Request.Types
-
-import qualified PostgREST.DbStructure.Relationship as Relationship
-
-import Protolude hiding (from)
-
-- | Builds the ReadRequest tree on a number of stages.
-- | Adds filters, order, limits on its respective nodes.
-- | Adds joins conditions obtained from resource embedding.
-readRequest :: Schema -> TableName -> Maybe Integer -> [Relationship] -> ApiRequest -> Either Error ReadRequest
-readRequest schema rootTableName maxRows allRels apiRequest  =
-  mapLeft ApiRequestError $
-  treeRestrictRange maxRows =<<
-  augmentRequestWithJoin schema rootRels =<<
-  (addFiltersOrdersRanges apiRequest . initReadRequest rootName =<< pRequestSelect sel)
-  where
-    sel = fromMaybe "*" $ iSelect apiRequest -- default to all columns requested (SELECT *) for a non existent ?select querystring param
-    (rootName, rootRels) = rootWithRels schema rootTableName allRels (iAction apiRequest)
-
-- Get the root table name with its relationships according to the Action type.
-- This is done because of the shape of the final SQL Query. The mutation cases
-- are wrapped in a WITH {sourceCTEName}(see Statements.hs).  So we need a FROM
-- {sourceCTEName} instead of FROM {tableName}.
-rootWithRels :: Schema -> TableName -> [Relationship] -> Action -> (QualifiedIdentifier, [Relationship])
-rootWithRels schema rootTableName allRels action = case action of
-  ActionRead _ -> (QualifiedIdentifier schema rootTableName, allRels) -- normal read case
-  _            -> (QualifiedIdentifier mempty _sourceCTEName, mapMaybe toSourceRel allRels ++ allRels) -- mutation cases and calling proc
-  where
-    _sourceCTEName = decodeUtf8 sourceCTEName
-    -- To enable embedding in the sourceCTEName cases we need to replace the
-    -- foreign key tableName in the Relationship with {sourceCTEName}. This way
-    -- findRel can find relationships with sourceCTEName.
-    toSourceRel :: Relationship -> Maybe Relationship
-    toSourceRel r@Relationship{relTable=t}
-      | rootTableName == tableName t = Just $ r {relTable=t {tableName=_sourceCTEName}}
-      | otherwise                    = Nothing
-
-- Build the initial tree with a Depth attribute so when a self join occurs we
-- can differentiate the parent and child tables by having an alias like
-- "table_depth", this is related to
-- http://github.com/PostgREST/postgrest/issues/987.
-initReadRequest :: QualifiedIdentifier -> [Tree SelectItem] -> ReadRequest
-initReadRequest rootQi =
-  foldr (treeEntry rootDepth) initial
-  where
-    rootDepth = 0
-    rootSchema = qiSchema rootQi
-    rootName = qiName rootQi
-    initial = Node (Select [] rootQi Nothing [] [] [] [] allRange, (rootName, Nothing, Nothing, Nothing, Nothing, rootDepth)) []
-    treeEntry :: Depth -> Tree SelectItem -> ReadRequest -> ReadRequest
-    treeEntry depth (Node fld@((fn, _),_,alias, hint, joinType) fldForest) (Node (q, i) rForest) =
-      let nxtDepth = succ depth in
-      case fldForest of
-        [] -> Node (q {select=fld:select q}, i) rForest
-        _  -> Node (q, i) $
-              foldr (treeEntry nxtDepth)
-              (Node (Select [] (QualifiedIdentifier rootSchema fn) Nothing [] [] [] [] allRange,
-                (fn, Nothing, alias, hint, joinType, nxtDepth)) [])
-              fldForest:rForest
-
-- | Enforces the `max-rows` config on the result
-treeRestrictRange :: Maybe Integer -> ReadRequest -> Either ApiRequestError ReadRequest
-treeRestrictRange maxRows request = pure $ nodeRestrictRange maxRows <$> request
-  where
-    nodeRestrictRange :: Maybe Integer -> ReadNode -> ReadNode
-    nodeRestrictRange m (q@Select {range_=r}, i) = (q{range_=restrictRange m r }, i)
-
-augmentRequestWithJoin :: Schema -> [Relationship] -> ReadRequest -> Either ApiRequestError ReadRequest
-augmentRequestWithJoin schema allRels request =
-  addRels schema allRels Nothing request
-  >>= addJoinConditions Nothing
-
-addRels :: Schema -> [Relationship] -> Maybe ReadRequest -> ReadRequest -> Either ApiRequestError ReadRequest
-addRels schema allRels parentNode (Node (query@Select{from=tbl}, (nodeName, _, alias, hint, joinType, depth)) forest) =
-  case parentNode of
-    Just (Node (Select{from=parentNodeQi}, _) _) ->
-      let newFrom r = if qiName tbl == nodeName then tableQi (relForeignTable r) else tbl
-          newReadNode = (\r -> (query{from=newFrom r}, (nodeName, Just r, alias, hint, joinType, depth))) <$> rel
-          rel = findRel schema allRels (qiName parentNodeQi) nodeName hint
-      in
-      Node <$> newReadNode <*> (updateForest . hush $ Node <$> newReadNode <*> pure forest)
-    _ ->
-      let rn = (query, (nodeName, Nothing, alias, Nothing, joinType, depth)) in
-      Node rn <$> updateForest (Just $ Node rn forest)
-  where
-    updateForest :: Maybe ReadRequest -> Either ApiRequestError [ReadRequest]
-    updateForest rq = addRels schema allRels rq `traverse` forest
-
-- Finds a relationship between an origin and a target in the request:
-- /origin?select=target(*) If more than one relationship is found then the
-- request is ambiguous and we return an error.  In that case the request can
-- be disambiguated by adding precision to the target or by using a hint:
-- /origin?select=target!hint(*) The elements will be matched according to
-- these rules:
-- origin = table / view
-- target = table / view / constraint / column-from-origin
-- hint   = table / view / constraint / column-from-origin / column-from-target
-- (hint can take table / view values to aid in finding the junction in an m2m relationship)
-findRel :: Schema -> [Relationship] -> NodeName -> NodeName -> Maybe Hint -> Either ApiRequestError Relationship
-findRel schema allRels origin target hint =
-  case rel of
-    []  -> Left $ NoRelBetween origin target
-    [r] -> Right r
-    -- Here we handle a self reference relationship to not cause a breaking
-    -- change: In a self reference we get two relationships with the same
-    -- foreign key and relTable/relFtable but with different
-    -- cardinalities(m2o/o2m) We output the O2M rel, the M2O rel can be
-    -- obtained by using the origin column as an embed hint.
-    rs@[rel0, rel1]  -> case (relCardinality rel0, relCardinality rel1, relTable rel0 == relTable rel1 && relForeignTable rel0 == relForeignTable rel1) of
-      (O2M cons1, M2O cons2, True) -> if cons1 == cons2 then Right rel0 else Left $ AmbiguousRelBetween origin target rs
-      (M2O cons1, O2M cons2, True) -> if cons1 == cons2 then Right rel1 else Left $ AmbiguousRelBetween origin target rs
-      _                            -> Left $ AmbiguousRelBetween origin target rs
-    rs -> Left $ AmbiguousRelBetween origin target rs
-  where
-    matchFKSingleCol hint_ cols = length cols == 1 && hint_ == (colName <$> head cols)
-    matchConstraint tar card = case card of
-      O2M cons -> tar == Just cons
-      M2O cons -> tar == Just cons
-      _        -> False
-    matchJunction hint_ card = case card of
-      M2M Junction{junTable} -> hint_ == Just (tableName junTable)
-      _                      -> False
-    rel = filter (
-      \Relationship{..} ->
-        -- Both relationship ends need to be on the exposed schema
-        schema == tableSchema relTable && schema == tableSchema relForeignTable &&
-        (
-          -- /projects?select=clients(*)
-          origin == tableName relTable  &&  -- projects
-          target == tableName relForeignTable ||  -- clients
-
-          -- /projects?select=projects_client_id_fkey(*)
-          (
-            origin == tableName relTable &&              -- projects
-            matchConstraint (Just target) relCardinality -- projects_client_id_fkey
-          ) ||
-          -- /projects?select=client_id(*)
-          (
-            origin == tableName relTable &&           -- projects
-            matchFKSingleCol (Just target) relColumns -- client_id
-          )
-        ) && (
-          isNothing hint || -- hint is optional
-
-          -- /projects?select=clients!projects_client_id_fkey(*)
-          matchConstraint hint relCardinality || -- projects_client_id_fkey
-
-          -- /projects?select=clients!client_id(*) or /projects?select=clients!id(*)
-          matchFKSingleCol hint relColumns  || -- client_id
-          matchFKSingleCol hint relForeignColumns || -- id
-
-          -- /users?select=tasks!users_tasks(*) many-to-many between users and tasks
-          matchJunction hint relCardinality -- users_tasks
-        )
-      ) allRels
-
-- previousAlias is only used for the case of self joins
-addJoinConditions :: Maybe Alias -> ReadRequest -> Either ApiRequestError ReadRequest
-addJoinConditions previousAlias (Node node@(query@Select{from=tbl}, nodeProps@(_, rel, _, _, _, depth)) forest) =
-  case rel of
-    Just r@Relationship{relCardinality=M2M Junction{junTable}} ->
-      let rq = augmentQuery r in
-      Node (rq{implicitJoins=tableQi junTable:implicitJoins rq}, nodeProps) <$> updatedForest
-    Just r -> Node (augmentQuery r, nodeProps) <$> updatedForest
-    Nothing -> Node node <$> updatedForest
-  where
-    newAlias = case Relationship.isSelfReference <$> rel of
-      Just True
-        | depth /= 0 -> Just (qiName tbl <> "_" <> show depth) -- root node doesn't get aliased
-        | otherwise  -> Nothing
-      _              -> Nothing
-    augmentQuery r =
-      foldr
-        (\jc rq@Select{joinConditions=jcs} -> rq{joinConditions=jc:jcs})
-        query{fromAlias=newAlias}
-        (getJoinConditions previousAlias newAlias r)
-    updatedForest = addJoinConditions newAlias `traverse` forest
-
-- previousAlias and newAlias are used in the case of self joins
-getJoinConditions :: Maybe Alias -> Maybe Alias -> Relationship -> [JoinCondition]
-getJoinConditions previousAlias newAlias (Relationship Table{tableSchema=tSchema, tableName=tN} cols Table{tableName=ftN} fCols card) =
-  case card of
-    M2M (Junction Table{tableName=jtn} _ jc1 _ jc2) ->
-      zipWith (toJoinCondition tN jtn) cols jc1 ++ zipWith (toJoinCondition ftN jtn) fCols jc2
-    _ ->
-      zipWith (toJoinCondition tN ftN) cols fCols
-  where
-    toJoinCondition :: Text -> Text -> Column -> Column -> JoinCondition
-    toJoinCondition tb ftb c fc =
-      let qi1 = removeSourceCTESchema tSchema tb
-          qi2 = removeSourceCTESchema tSchema ftb in
-        JoinCondition (maybe qi1 (QualifiedIdentifier mempty) previousAlias, colName c)
-                      (maybe qi2 (QualifiedIdentifier mempty) newAlias, colName fc)
-
-    -- On mutation and calling proc cases we wrap the target table in a WITH
-    -- {sourceCTEName} if this happens remove the schema `FROM
-    -- "schema"."{sourceCTEName}"` and use only the `FROM "{sourceCTEName}"`.
-    -- If the schema remains the FROM would be invalid.
-    removeSourceCTESchema :: Schema -> TableName -> QualifiedIdentifier
-    removeSourceCTESchema schema tbl = QualifiedIdentifier (if tbl == decodeUtf8 sourceCTEName then mempty else schema) tbl
-
-addFiltersOrdersRanges :: ApiRequest -> ReadRequest -> Either ApiRequestError ReadRequest
-addFiltersOrdersRanges apiRequest rReq = do
-  rFlts <- foldr addFilter rReq <$> filters
-  rOrds <- foldr addOrder rFlts <$> orders
-  rRngs <- foldr addRange rOrds <$> ranges
-  foldr addLogicTree rRngs      <$> logicForest
-  where
-    filters :: Either ApiRequestError [(EmbedPath, Filter)]
-    filters = pRequestFilter `traverse` flts
-    orders :: Either ApiRequestError [(EmbedPath, [OrderTerm])]
-    orders = pRequestOrder `traverse` iOrder apiRequest
-    ranges :: Either ApiRequestError [(EmbedPath, NonnegRange)]
-    ranges = pRequestRange `traverse` M.toList (iRange apiRequest)
-    logicForest :: Either ApiRequestError [(EmbedPath, LogicTree)]
-    logicForest = pRequestLogicTree `traverse` logFrst
-    action = iAction apiRequest
-    -- there can be no filters on the root table when we are doing insert/update/delete
-    (flts, logFrst) =
-      case action of
-        ActionInvoke _ -> (iFilters apiRequest, iLogic apiRequest)
-        ActionRead _   -> (iFilters apiRequest, iLogic apiRequest)
-        _              -> join (***) (filter (( "." `isInfixOf` ) . fst)) (iFilters apiRequest, iLogic apiRequest)
-
-addFilterToNode :: Filter -> ReadRequest -> ReadRequest
-addFilterToNode flt (Node (q@Select {where_=lf}, i) f) = Node (q{where_=addFilterToLogicForest flt lf}::ReadQuery, i) f
-
-addFilter :: (EmbedPath, Filter) -> ReadRequest -> ReadRequest
-addFilter = addProperty addFilterToNode
-
-addOrderToNode :: [OrderTerm] -> ReadRequest -> ReadRequest
-addOrderToNode o (Node (q,i) f) = Node (q{order=o}, i) f
-
-addOrder :: (EmbedPath, [OrderTerm]) -> ReadRequest -> ReadRequest
-addOrder = addProperty addOrderToNode
-
-addRangeToNode :: NonnegRange -> ReadRequest -> ReadRequest
-addRangeToNode r (Node (q,i) f) = Node (q{range_=r}, i) f
-
-addRange :: (EmbedPath, NonnegRange) -> ReadRequest -> ReadRequest
-addRange = addProperty addRangeToNode
-
-addLogicTreeToNode :: LogicTree -> ReadRequest -> ReadRequest
-addLogicTreeToNode t (Node (q@Select{where_=lf},i) f) = Node (q{where_=t:lf}::ReadQuery, i) f
-
-addLogicTree :: (EmbedPath, LogicTree) -> ReadRequest -> ReadRequest
-addLogicTree = addProperty addLogicTreeToNode
-
-addProperty :: (a -> ReadRequest -> ReadRequest) -> (EmbedPath, a) -> ReadRequest -> ReadRequest
-addProperty f ([], a) rr = f a rr
-addProperty f (targetNodeName:remainingPath, a) (Node rn forest) =
-  case pathNode of
-    Nothing -> Node rn forest -- the property is silenty dropped in the Request does not contain the required path
-    Just tn -> Node rn (addProperty f (remainingPath, a) tn:delete tn forest)
-  where
-    pathNode = find (\(Node (_,(nodeName,_,alias,_,_, _)) _) -> nodeName == targetNodeName || alias == Just targetNodeName) forest
-
-mutateRequest :: Schema -> TableName -> ApiRequest -> [FieldName] -> ReadRequest -> Either Error MutateRequest
-mutateRequest schema tName apiRequest pkCols readReq = mapLeft ApiRequestError $
-  case action of
-    ActionCreate -> do
-        confCols <- case iOnConflict apiRequest of
-            Nothing    -> pure pkCols
-            Just param -> pRequestOnConflict param
-        pure $ Insert qi (iColumns apiRequest) body ((,) <$> iPreferResolution apiRequest <*> Just confCols) [] returnings
-    ActionUpdate -> Update qi (iColumns apiRequest) body  <$> combinedLogic <*> pure returnings
-    ActionSingleUpsert ->
-      (\flts ->
-        if null (iLogic apiRequest) &&
-           S.fromList (fst <$> iFilters apiRequest) == S.fromList pkCols &&
-           not (null (S.fromList pkCols)) &&
-           all (\case
-              Filter _ (OpExpr False (Op "eq" _)) -> True
-              _                                   -> False) flts
-          then Insert qi (iColumns apiRequest) body (Just (MergeDuplicates, pkCols)) <$> combinedLogic <*> pure returnings
-        else
-          Left InvalidFilters) =<< filters
-    ActionDelete -> Delete qi <$> combinedLogic <*> pure returnings
-    _            -> Left UnsupportedVerb
-  where
-    qi = QualifiedIdentifier schema tName
-    action = iAction apiRequest
-    returnings =
-      if iPreferRepresentation apiRequest == None
-        then []
-        else returningCols readReq pkCols
-    filters = map snd <$> pRequestFilter `traverse` mutateFilters
-    logic = map snd <$> pRequestLogicTree `traverse` logicFilters
-    combinedLogic = foldr addFilterToLogicForest <$> logic <*> filters
-    -- update/delete filters can be only on the root table
-    (mutateFilters, logicFilters) = join (***) onlyRoot (iFilters apiRequest, iLogic apiRequest)
-    onlyRoot = filter (not . ( "." `isInfixOf` ) . fst)
-    body = payRaw <$> iPayload apiRequest -- the body is assumed to be json at this stage(ApiRequest validates)
-
-callRequest :: ProcDescription -> ApiRequest -> ReadRequest -> CallRequest
-callRequest proc apiReq readReq = FunctionCall {
-  funCQi = QualifiedIdentifier (pdSchema proc) (pdName proc)
-, funCParams = callParams
-, funCArgs = payRaw <$> iPayload apiReq
-, funCScalar = procReturnsScalar proc
-, funCMultipleCall = iPreferParameters apiReq == Just MultipleObjects
-, funCReturning = returningCols readReq []
-}
-  where
-    paramsAsSingleObject = iPreferParameters apiReq == Just SingleObject
-    callParams = case pdParams proc of
-      [prm] | paramsAsSingleObject -> OnePosParam prm
-            | ppName prm == mempty -> OnePosParam prm
-            | otherwise            -> KeyParams $ specifiedParams [prm]
-      prms  -> KeyParams $ specifiedParams prms
-    specifiedParams params = filter (\x -> ppName x `S.member` iColumns apiReq) params
-
-returningCols :: ReadRequest -> [FieldName] -> [FieldName]
-returningCols rr@(Node _ forest) pkCols
-  -- if * is part of the select, we must not add pk or fk columns manually -
-  -- otherwise those would be selected and output twice
-  | "*" `elem` fldNames = ["*"]
-  | otherwise           = returnings
-  where
-    fldNames = fstFieldNames rr
-    -- Without fkCols, when a mutateRequest to
-    -- /projects?select=name,clients(name) occurs, the RETURNING SQL part would
-    -- be `RETURNING name`(see QueryBuilder).  This would make the embedding
-    -- fail because the following JOIN would need the "client_id" column from
-    -- projects.  So this adds the foreign key columns to ensure the embedding
-    -- succeeds, result would be `RETURNING name, client_id`.
-    fkCols = concat $ mapMaybe (\case
-        Node (_, (_, Just Relationship{relColumns=cols}, _, _, _, _)) _ -> Just cols
-        _                                                        -> Nothing
-      ) forest
-    -- However if the "client_id" is present, e.g. mutateRequest to
-    -- /projects?select=client_id,name,clients(name) we would get `RETURNING
-    -- client_id, name, client_id` and then we would produce the "column
-    -- reference \"client_id\" is ambiguous" error from PostgreSQL. So we
-    -- deduplicate with Set: We are adding the primary key columns as well to
-    -- make sure, that a proper location header can always be built for
-    -- INSERT/POST
-    returnings = S.toList . S.fromList $ fldNames ++ (colName <$> fkCols) ++ pkCols
-
-- Traditional filters(e.g. id=eq.1) are added as root nodes of the LogicTree
-- they are later concatenated with AND in the QueryBuilder
-addFilterToLogicForest :: Filter -> [LogicTree] -> [LogicTree]
-addFilterToLogicForest flt lf = Stmnt flt : lf
@@ -1,294 +0,0 @@
-{-|
-Module      : PostgREST.Request.Parsers
-Description : PostgREST parser combinators
-
-This module is in charge of parsing all the querystring values in an url, e.g. the select, id, order in `/projects?select=id,name&id=eq.1&order=id,name.desc`.
-}
-module PostgREST.Request.Parsers
-  ( pColumns
-  , pLogicPath
-  , pLogicSingleVal
-  , pLogicTree
-  , pOrder
-  , pOrderTerm
-  , pRequestColumns
-  , pRequestFilter
-  , pRequestLogicTree
-  , pRequestOnConflict
-  , pRequestOrder
-  , pRequestRange
-  , pRequestSelect
-  , pSingleVal
-  , pTreePath
-  ) where
-
-import qualified Data.HashMap.Strict as M
-import qualified Data.Set            as S
-
-import Data.Either.Combinators       (mapLeft)
-import Data.Foldable                 (foldl1)
-import Data.List                     (init, last)
-import Data.Text                     (intercalate, replace, strip)
-import Data.Tree                     (Tree (..))
-import Text.Parsec.Error             (errorMessages,
-                                      showErrorMessages)
-import Text.ParserCombinators.Parsec (GenParser, ParseError, Parser,
-                                      anyChar, between, char, digit,
-                                      eof, errorPos, letter,
-                                      lookAhead, many1, noneOf,
-                                      notFollowedBy, oneOf, option,
-                                      optionMaybe, parse, sepBy1,
-                                      string, try, (<?>))
-
-import PostgREST.DbStructure.Identifiers (FieldName)
-import PostgREST.Error                   (ApiRequestError (ParseRequestError))
-import PostgREST.Query.SqlFragment       (ftsOperators, operators)
-import PostgREST.RangeQuery              (NonnegRange)
-
-import PostgREST.Request.Types
-
-import Protolude hiding (intercalate, option, replace, try)
-
-pRequestSelect :: Text -> Either ApiRequestError [Tree SelectItem]
-pRequestSelect selStr =
-  mapError $ parse pFieldForest ("failed to parse select parameter (" <> toS selStr <> ")") (toS selStr)
-
-pRequestOnConflict :: Text -> Either ApiRequestError  [FieldName]
-pRequestOnConflict oncStr =
-  mapError $ parse pColumns ("failed to parse on_conflict parameter (" <> toS oncStr <> ")") (toS oncStr)
-
-pRequestFilter :: (Text, Text) -> Either ApiRequestError (EmbedPath, Filter)
-pRequestFilter (k, v) = mapError $ (,) <$> path <*> (Filter <$> fld <*> oper)
-  where
-    treePath = parse pTreePath ("failed to parser tree path (" ++ toS k ++ ")") $ toS k
-    oper = parse (pOpExpr pSingleVal) ("failed to parse filter (" ++ toS v ++ ")") $ toS v
-    path = fst <$> treePath
-    fld = snd <$> treePath
-
-pRequestOrder :: (Text, Text) -> Either ApiRequestError (EmbedPath, [OrderTerm])
-pRequestOrder (k, v) = mapError $ (,) <$> path <*> ord'
-  where
-    treePath = parse pTreePath ("failed to parser tree path (" ++ toS k ++ ")") $ toS k
-    path = fst <$> treePath
-    ord' = parse pOrder ("failed to parse order (" ++ toS v ++ ")") $ toS v
-
-pRequestRange :: (Text, NonnegRange) -> Either ApiRequestError (EmbedPath, NonnegRange)
-pRequestRange (k, v) = mapError $ (,) <$> path <*> pure v
-  where
-    treePath = parse pTreePath ("failed to parser tree path (" ++ toS k ++ ")") $ toS k
-    path = fst <$> treePath
-
-pRequestLogicTree :: (Text, Text) -> Either ApiRequestError (EmbedPath, LogicTree)
-pRequestLogicTree (k, v) = mapError $ (,) <$> embedPath <*> logicTree
-  where
-    path = parse pLogicPath ("failed to parser logic path (" ++ toS k ++ ")") $ toS k
-    embedPath = fst <$> path
-    logicTree = do
-      op <- snd <$> path
-      -- Concat op and v to make pLogicTree argument regular,
-      -- in the form of "?and=and(.. , ..)" instead of "?and=(.. , ..)"
-      parse pLogicTree ("failed to parse logic tree (" ++ toS v ++ ")") $ toS (op <> v)
-
-pRequestColumns :: Maybe Text -> Either ApiRequestError (Maybe (S.Set FieldName))
-pRequestColumns colStr =
-  case colStr of
-    Just str ->
-      mapError $ Just . S.fromList <$> parse pColumns ("failed to parse columns parameter (" <> toS str <> ")") (toS str)
-    _ -> Right Nothing
-
-ws :: Parser Text
-ws = toS <$> many (oneOf " \t")
-
-lexeme :: Parser a -> Parser a
-lexeme p = ws *> p <* ws
-
-pTreePath :: Parser (EmbedPath, Field)
-pTreePath = do
-  p <- pFieldName `sepBy1` pDelimiter
-  jp <- option [] pJsonPath
-  return (init p, (last p, jp))
-
-pFieldForest :: Parser [Tree SelectItem]
-pFieldForest = pFieldTree `sepBy1` lexeme (char ',')
-  where
-    pFieldTree :: Parser (Tree SelectItem)
-    pFieldTree =  try (Node <$> pRelationSelect <*> between (char '(') (char ')') pFieldForest) <|>
-                  Node <$> pFieldSelect <*> pure []
-
-pStar :: Parser Text
-pStar = string "*" $> "*"
-
-pFieldName :: Parser Text
-pFieldName =
-  pQuotedValue <|>
-  intercalate "-" . map toS <$> (many1 (letter <|> digit <|> oneOf "_ ") `sepBy1` dash) <?>
-  "field name (* or [a..z0..9_])"
-  where
-    isDash :: GenParser Char st ()
-    isDash = try ( char '-' >> notFollowedBy (char '>') )
-    dash :: Parser Char
-    dash = isDash $> '-'
-
-pJsonPath :: Parser JsonPath
-pJsonPath = many pJsonOperation
-  where
-    pJsonOperation :: Parser JsonOperation
-    pJsonOperation = pJsonArrow <*> pJsonOperand
-
-    pJsonArrow   =
-      try (string "->>" $> J2Arrow) <|>
-      try (string "->" $> JArrow)
-
-    pJsonOperand =
-      let pJKey = JKey . toS <$> pFieldName
-          pJIdx = JIdx . toS <$> ((:) <$> option '+' (char '-') <*> many1 digit) <* pEnd
-          pEnd = try (void $ lookAhead (string "->")) <|>
-                 try (void $ lookAhead (string "::")) <|>
-                 try eof in
-      try pJIdx <|> try pJKey
-
-pField :: Parser Field
-pField = lexeme $ (,) <$> pFieldName <*> option [] pJsonPath
-
-aliasSeparator :: Parser ()
-aliasSeparator = char ':' >> notFollowedBy (char ':')
-
-pRelationSelect :: Parser SelectItem
-pRelationSelect = lexeme $ try ( do
-    alias <- optionMaybe ( try(pFieldName <* aliasSeparator) )
-    fld <- pField
-    prm1 <- optionMaybe pEmbedParam
-    prm2 <- optionMaybe pEmbedParam
-    return (fld, Nothing, alias, embedParamHint prm1 <|> embedParamHint prm2, embedParamJoin prm1 <|> embedParamJoin prm2)
-  )
-  where
-    pEmbedParam :: Parser EmbedParam
-    pEmbedParam =
-      char '!' *> (
-        try (string "left"  $> EPJoinType JTLeft)  <|>
-        try (string "inner" $> EPJoinType JTInner) <|>
-        try (EPHint <$> pFieldName))
-    embedParamHint prm = case prm of
-      Just (EPHint hint) -> Just hint
-      _                  -> Nothing
-    embedParamJoin prm = case prm of
-      Just (EPJoinType jt) -> Just jt
-      _                    -> Nothing
-
-pFieldSelect :: Parser SelectItem
-pFieldSelect = lexeme $
-  try (
-    do
-      alias <- optionMaybe ( try(pFieldName <* aliasSeparator) )
-      fld <- pField
-      cast' <- optionMaybe (string "::" *> many letter)
-      return (fld, toS <$> cast', alias, Nothing, Nothing)
-  )
-  <|> do
-    s <- pStar
-    return ((s, []), Nothing, Nothing, Nothing, Nothing)
-
-pOpExpr :: Parser SingleVal -> Parser OpExpr
-pOpExpr pSVal = try ( string "not" *> pDelimiter *> (OpExpr True <$> pOperation)) <|> OpExpr False <$> pOperation
-  where
-    pOperation :: Parser Operation
-    pOperation =
-          Op . toS <$> foldl1 (<|>) (try . ((<* pDelimiter) . string) . toS <$> M.keys ops) <*> pSVal
-      <|> In <$> (try (string "in" *> pDelimiter) *> pListVal)
-      <|> Is <$> (try (string "is" *> pDelimiter) *> pTriVal)
-      <|> pFts
-      <?> "operator (eq, gt, ...)"
-
-    pTriVal = try (string "null"    $> TriNull)
-          <|> try (string "unknown" $> TriUnknown)
-          <|> try (string "true"    $> TriTrue)
-          <|> try (string "false"   $> TriFalse)
-          <?> "null or trilean value (unknown, true, false)"
-
-    pFts = do
-      op   <- foldl1 (<|>) (try . string . toS <$> ftsOps)
-      lang <- optionMaybe $ try (between (char '(') (char ')') (many (letter <|> digit <|> oneOf "_")))
-      pDelimiter >> Fts (toS op) (toS <$> lang) <$> pSVal
-
-    ops = M.filterWithKey (const . flip notElem ("in":"is":ftsOps)) operators
-    ftsOps = M.keys ftsOperators
-
-pSingleVal :: Parser SingleVal
-pSingleVal = toS <$> many anyChar
-
-pListVal :: Parser ListVal
-pListVal = lexeme (char '(') *> pListElement `sepBy1` char ',' <* lexeme (char ')')
-
-pListElement :: Parser Text
-pListElement = try (pQuotedValue <* notFollowedBy (noneOf ",)")) <|> (toS <$> many (noneOf ",)"))
-
-pQuotedValue :: Parser Text
-pQuotedValue = toS <$> (char '"' *> many pCharsOrSlashed <* char '"')
-  where
-    pCharsOrSlashed = noneOf "\\\"" <|> (char '\\' *> anyChar)
-
-pDelimiter :: Parser Char
-pDelimiter = char '.' <?> "delimiter (.)"
-
-pOrder :: Parser [OrderTerm]
-pOrder = lexeme pOrderTerm `sepBy1` char ','
-
-pOrderTerm :: Parser OrderTerm
-pOrderTerm = do
-  fld <- pField
-  dir <- optionMaybe $
-         try (pDelimiter *> string "asc" $> OrderAsc) <|>
-         try (pDelimiter *> string "desc" $> OrderDesc)
-  nls <- optionMaybe pNulls <* pEnd <|>
-         pEnd $> Nothing
-  return $ OrderTerm fld dir nls
-  where
-    pNulls = try (pDelimiter *> string "nullsfirst" $> OrderNullsFirst) <|>
-             try (pDelimiter *> string "nullslast"  $> OrderNullsLast)
-    pEnd = try (void $ lookAhead (char ',')) <|>
-           try eof
-
-pLogicTree :: Parser LogicTree
-pLogicTree = Stmnt <$> try pLogicFilter
-             <|> Expr <$> pNot <*> pLogicOp <*> (lexeme (char '(') *> pLogicTree `sepBy1` lexeme (char ',') <* lexeme (char ')'))
-  where
-    pLogicFilter :: Parser Filter
-    pLogicFilter = Filter <$> pField <* pDelimiter <*> pOpExpr pLogicSingleVal
-    pNot :: Parser Bool
-    pNot = try (string "not" *> pDelimiter $> True)
-           <|> pure False
-           <?> "negation operator (not)"
-    pLogicOp :: Parser LogicOperator
-    pLogicOp = try (string "and" $> And)
-               <|> string "or" $> Or
-               <?> "logic operator (and, or)"
-
-pLogicSingleVal :: Parser SingleVal
-pLogicSingleVal = try (pQuotedValue <* notFollowedBy (noneOf ",)")) <|> try pPgArray <|> (toS <$> many (noneOf ",)"))
-  where
-    pPgArray :: Parser Text
-    pPgArray =  do
-      a <- string "{"
-      b <- many (noneOf "{}")
-      c <- string "}"
-      pure (toS $ a ++ b ++ c)
-
-pLogicPath :: Parser (EmbedPath, Text)
-pLogicPath = do
-  path <- pFieldName `sepBy1` pDelimiter
-  let op = last path
-      notOp = "not." <> op
-  return (filter (/= "not") (init path), if "not" `elem` path then notOp else op)
-
-pColumns :: Parser [FieldName]
-pColumns = pFieldName `sepBy1` lexeme (char ',')
-
-mapError :: Either ParseError a -> Either ApiRequestError a
-mapError = mapLeft translateError
-  where
-    translateError e =
-      ParseRequestError message details
-      where
-        message = show $ errorPos e
-        details = strip $ replace "\n" " " $ toS
-           $ showErrorMessages "or" "unknown parse error" "expecting" "unexpected" "end of input" (errorMessages e)
@@ -1,232 +0,0 @@
-{-# LANGUAGE DuplicateRecordFields #-}
-module PostgREST.Request.Types
-  ( Alias
-  , Depth
-  , EmbedParam(..)
-  , EmbedPath
-  , Field
-  , Filter(..)
-  , Hint
-  , CallQuery(..)
-  , CallParams(..)
-  , CallRequest
-  , JoinCondition(..)
-  , JoinType(..)
-  , JsonOperand(..)
-  , JsonOperation(..)
-  , JsonPath
-  , ListVal
-  , LogicOperator(..)
-  , LogicTree(..)
-  , MutateQuery(..)
-  , MutateRequest
-  , NodeName
-  , OpExpr(..)
-  , Operation (..)
-  , OrderDirection(..)
-  , OrderNulls(..)
-  , OrderTerm(..)
-  , ReadNode
-  , ReadQuery(..)
-  , ReadRequest
-  , SelectItem
-  , SingleVal
-  , TrileanVal(..)
-  , fstFieldNames
-  ) where
-
-import qualified Data.ByteString.Lazy as LBS
-import qualified Data.Set             as S
-
-import Data.Tree (Tree (..))
-
-import PostgREST.DbStructure.Identifiers  (FieldName,
-                                           QualifiedIdentifier)
-import PostgREST.DbStructure.Proc         (ProcParam (..))
-import PostgREST.DbStructure.Relationship (Relationship)
-import PostgREST.RangeQuery               (NonnegRange)
-import PostgREST.Request.Preferences      (PreferResolution)
-
-import Protolude
-
-
-type ReadRequest = Tree ReadNode
-type MutateRequest = MutateQuery
-type CallRequest = CallQuery
-
-type ReadNode =
-  (ReadQuery, (NodeName, Maybe Relationship, Maybe Alias, Maybe Hint, Maybe JoinType, Depth))
-
-type NodeName = Text
-type Depth = Integer
-
-data ReadQuery = Select
-  { select         :: [SelectItem]
-  , from           :: QualifiedIdentifier
-  -- ^ A table alias is used in case of self joins
-  , fromAlias      :: Maybe Alias
-  -- ^ Only used for Many to Many joins. Parent and Child joins use explicit joins.
-  , implicitJoins  :: [QualifiedIdentifier]
-  , where_         :: [LogicTree]
-  , joinConditions :: [JoinCondition]
-  , order          :: [OrderTerm]
-  , range_         :: NonnegRange
-  }
-  deriving (Eq)
-
-data JoinCondition =
-  JoinCondition
-    (QualifiedIdentifier, FieldName)
-    (QualifiedIdentifier, FieldName)
-  deriving (Eq)
-
-data OrderTerm = OrderTerm
-  { otTerm      :: Field
-  , otDirection :: Maybe OrderDirection
-  , otNullOrder :: Maybe OrderNulls
-  }
-  deriving (Eq)
-
-data OrderDirection
-  = OrderAsc
-  | OrderDesc
-  deriving (Eq)
-
-data OrderNulls
-  = OrderNullsFirst
-  | OrderNullsLast
-  deriving (Eq)
-
-data MutateQuery
-  = Insert
-      { in_        :: QualifiedIdentifier
-      , insCols    :: S.Set FieldName
-      , insBody    :: Maybe LBS.ByteString
-      , onConflict :: Maybe (PreferResolution, [FieldName])
-      , where_     :: [LogicTree]
-      , returning  :: [FieldName]
-      }
-  | Update
-      { in_       :: QualifiedIdentifier
-      , updCols   :: S.Set FieldName
-      , updBody   :: Maybe LBS.ByteString
-      , where_    :: [LogicTree]
-      , returning :: [FieldName]
-      }
-  | Delete
-      { in_       :: QualifiedIdentifier
-      , where_    :: [LogicTree]
-      , returning :: [FieldName]
-      }
-
-data CallQuery = FunctionCall
-  { funCQi           :: QualifiedIdentifier
-  , funCParams       :: CallParams
-  , funCArgs         :: Maybe LBS.ByteString
-  , funCScalar       :: Bool
-  , funCMultipleCall :: Bool
-  , funCReturning    :: [FieldName]
-  }
-
-data CallParams
-  = KeyParams [ProcParam] -- ^ Call with key params: func(a := val1, b:= val2)
-  | OnePosParam ProcParam -- ^ Call with positional params(only one supported): func(val)
-
-- | The select value in `/tbl?select=alias:field::cast`
-type SelectItem = (Field, Maybe Cast, Maybe Alias, Maybe Hint, Maybe JoinType)
-
-type Field = (FieldName, JsonPath)
-type Cast = Text
-type Alias = Text
-type Hint = Text
-
-data EmbedParam
-  -- | Disambiguates an embedding operation when there's multiple relationships
-  -- between two tables. Can be the name of a foreign key constraint, column
-  -- name or the junction in an m2m relationship.
-  = EPHint Hint
-  | EPJoinType JoinType
-
-data JoinType
-  = JTInner
-  | JTLeft
-  deriving Eq
-
-- | Path of the embedded levels, e.g "clients.projects.name=eq.." gives Path
-- ["clients", "projects"]
-type EmbedPath = [Text]
-
-- | Json path operations as specified in
-- https://www.postgresql.org/docs/current/static/functions-json.html
-type JsonPath = [JsonOperation]
-
-- | Represents the single arrow `->` or double arrow `->>` operators
-data JsonOperation
-  = JArrow { jOp :: JsonOperand }
-  | J2Arrow { jOp :: JsonOperand }
-  deriving (Eq)
-
-- | Represents the key(`->'key'`) or index(`->'1`::int`), the index is Text
-- because we reuse our escaping functons and let pg do the casting with
-- '1'::int
-data JsonOperand
-  = JKey { jVal :: Text }
-  | JIdx { jVal :: Text }
-  deriving (Eq)
-
-- First level FieldNames(e.g get a,b from /table?select=a,b,other(c,d))
-fstFieldNames :: ReadRequest -> [FieldName]
-fstFieldNames (Node (sel, _) _) =
-  fst . (\(f, _, _, _, _) -> f) <$> select sel
-
-
-- | Boolean logic expression tree e.g. "and(name.eq.N,or(id.eq.1,id.eq.2))" is:
--
--            And
--           /   \
--  name.eq.N     Or
--               /  \
--         id.eq.1   id.eq.2
-data LogicTree
-  = Expr Bool LogicOperator [LogicTree]
-  | Stmnt Filter
-  deriving (Eq)
-
-data LogicOperator
-  = And
-  | Or
-  deriving Eq
-
-data Filter = Filter
-  { field  :: Field
-  , opExpr :: OpExpr
-  }
-  deriving (Eq)
-
-data OpExpr =
-  OpExpr Bool Operation
-  deriving (Eq)
-
-data Operation
-  = Op Operator SingleVal
-  | In ListVal
-  | Is TrileanVal
-  | Fts Operator (Maybe Language) SingleVal
-  deriving (Eq)
-
-type Operator = Text
-type Language = Text
-
-- | Represents a single value in a filter, e.g. id=eq.singleval
-type SingleVal = Text
-
-- | Represents a list value in a filter, e.g. id=in.(val1,val2,val3)
-type ListVal = [Text]
-
-- | Three-valued logic values
-data TrileanVal
-  = TriTrue
-  | TriFalse
-  | TriNull
-  | TriUnknown
-  deriving Eq
@@ -0,0 +1,288 @@
+{-# LANGUAGE NamedFieldPuns  #-}
+{-# LANGUAGE RecordWildCards #-}
+module PostgREST.Response
+  ( createResponse
+  , deleteResponse
+  , infoResponse
+  , invokeResponse
+  , openApiResponse
+  , readResponse
+  , singleUpsertResponse
+  , updateResponse
+  , addRetryHint
+  , isServiceUnavailable
+  , optionalRollback
+  ) where
+
+import qualified Data.Aeson                as JSON
+import qualified Data.ByteString.Char8     as BS
+import qualified Data.ByteString.Lazy      as LBS
+import qualified Data.HashMap.Strict       as HM
+import           Data.Text.Read            (decimal)
+import qualified Network.HTTP.Types.Header as HTTP
+import qualified Network.HTTP.Types.Status as HTTP
+import qualified Network.HTTP.Types.URI    as HTTP
+import qualified Network.Wai               as Wai
+
+import qualified PostgREST.Error            as Error
+import qualified PostgREST.MediaType        as MediaType
+import qualified PostgREST.RangeQuery       as RangeQuery
+import qualified PostgREST.Response.OpenAPI as OpenAPI
+
+import PostgREST.ApiRequest              (ApiRequest (..),
+                                          InvokeMethod (..),
+                                          Target (..))
+import PostgREST.ApiRequest.Preferences  (PreferRepresentation (..),
+                                          PreferTransaction (..),
+                                          shouldCount,
+                                          toAppliedHeader)
+import PostgREST.ApiRequest.QueryParams  (QueryParams (..))
+import PostgREST.Config                  (AppConfig (..))
+import PostgREST.MediaType               (MediaType (..))
+import PostgREST.Plan                    (MutateReadPlan (..))
+import PostgREST.Plan.MutatePlan         (MutatePlan (..))
+import PostgREST.Query.Statements        (ResultSet (..))
+import PostgREST.Response.GucHeader      (GucHeader, unwrapGucHeader)
+import PostgREST.SchemaCache             (SchemaCache (..))
+import PostgREST.SchemaCache.Identifiers (QualifiedIdentifier (..),
+                                          Schema)
+import PostgREST.SchemaCache.Proc        (ProcDescription (..),
+                                          ProcVolatility (..),
+                                          ProcsMap)
+import PostgREST.SchemaCache.Table       (Table (..), TablesMap)
+
+import qualified PostgREST.ApiRequest.Types as ApiRequestTypes
+import qualified PostgREST.SchemaCache.Proc as Proc
+
+import Protolude      hiding (Handler, toS)
+import Protolude.Conv (toS)
+
+readResponse :: Bool -> QualifiedIdentifier -> ApiRequest -> ResultSet -> Wai.Response
+readResponse headersOnly identifier ctxApiRequest@ApiRequest{..} resultSet = case resultSet of
+  RSStandard{..} -> do
+    let
+      (status, contentRange) = RangeQuery.rangeStatusHeader iTopLevelRange rsQueryTotal rsTableTotal
+      response = gucResponse rsGucStatus rsGucHeaders
+      headers =
+        [ contentRange
+        , ( "Content-Location"
+          , "/"
+              <> toUtf8 (qiName identifier)
+              <> if BS.null (qsCanonical iQueryParams) then mempty else "?" <> qsCanonical iQueryParams
+          )
+        ]
+        ++ contentTypeHeaders ctxApiRequest
+      rsOrErrBody = if status == HTTP.status416
+        then Error.errorPayload $ Error.ApiRequestError $ ApiRequestTypes.InvalidRange
+          $ ApiRequestTypes.OutOfBounds (show $ RangeQuery.rangeOffset iTopLevelRange) (maybe "0" show rsTableTotal)
+        else LBS.fromStrict rsBody
+
+    response status headers $ if headersOnly then mempty else rsOrErrBody
+
+  RSPlan plan ->
+    Wai.responseLBS HTTP.status200 (contentTypeHeaders ctxApiRequest) $ LBS.fromStrict plan
+
+createResponse :: QualifiedIdentifier -> MutateReadPlan -> ApiRequest -> ResultSet -> Wai.Response
+createResponse QualifiedIdentifier{..} MutateReadPlan{mrMutatePlan} ctxApiRequest@ApiRequest{..} resultSet = case resultSet of
+  RSStandard{..} -> do
+    let
+      pkCols = case mrMutatePlan of { Insert{insPkCols} -> insPkCols; _ -> mempty;}
+      response = gucResponse rsGucStatus rsGucHeaders
+      headers =
+        catMaybes
+          [ if null rsLocation then
+              Nothing
+            else
+              Just
+                ( HTTP.hLocation
+                , "/"
+                    <> toUtf8 qiName
+                    <> HTTP.renderSimpleQuery True rsLocation
+                )
+          , Just . RangeQuery.contentRangeH 1 0 $
+              if shouldCount iPreferCount then Just rsQueryTotal else Nothing
+          , if null pkCols && isNothing (qsOnConflict iQueryParams) then
+              Nothing
+            else
+              toAppliedHeader <$> iPreferResolution
+          ]
+
+    if iPreferRepresentation == Full then
+      response HTTP.status201 (headers ++ contentTypeHeaders ctxApiRequest) (LBS.fromStrict rsBody)
+    else
+      response HTTP.status201 headers mempty
+
+  RSPlan plan ->
+    Wai.responseLBS HTTP.status200 (contentTypeHeaders ctxApiRequest) $ LBS.fromStrict plan
+
+updateResponse :: ApiRequest -> ResultSet -> Wai.Response
+updateResponse ctxApiRequest@ApiRequest{..} resultSet = case resultSet of
+  RSStandard{..} -> do
+    let
+      response = gucResponse rsGucStatus rsGucHeaders
+      contentRangeHeader =
+        RangeQuery.contentRangeH 0 (rsQueryTotal - 1) $
+          if shouldCount iPreferCount then Just rsQueryTotal else Nothing
+      headers = [contentRangeHeader]
+
+    if iPreferRepresentation == Full then
+        response HTTP.status200
+          (headers ++ contentTypeHeaders ctxApiRequest)
+          (LBS.fromStrict rsBody)
+      else
+        response HTTP.status204 headers mempty
+
+  RSPlan plan ->
+    Wai.responseLBS HTTP.status200 (contentTypeHeaders ctxApiRequest) $ LBS.fromStrict plan
+
+singleUpsertResponse :: ApiRequest -> ResultSet -> Wai.Response
+singleUpsertResponse ctxApiRequest@ApiRequest{..} resultSet = case resultSet of
+  RSStandard {..} -> do
+    let
+      response = gucResponse rsGucStatus rsGucHeaders
+
+    if iPreferRepresentation == Full then
+      response HTTP.status200 (contentTypeHeaders ctxApiRequest) (LBS.fromStrict rsBody)
+    else
+      response HTTP.status204 [] mempty
+
+  RSPlan plan ->
+    Wai.responseLBS HTTP.status200 (contentTypeHeaders ctxApiRequest) $ LBS.fromStrict plan
+
+deleteResponse :: ApiRequest -> ResultSet -> Wai.Response
+deleteResponse ctxApiRequest@ApiRequest{..} resultSet = case resultSet of
+  RSStandard {..} -> do
+    let
+      response = gucResponse rsGucStatus rsGucHeaders
+      contentRangeHeader =
+        RangeQuery.contentRangeH 1 0 $
+          if shouldCount iPreferCount then Just rsQueryTotal else Nothing
+      headers = [contentRangeHeader]
+
+    if iPreferRepresentation == Full then
+        response HTTP.status200
+          (headers ++ contentTypeHeaders ctxApiRequest)
+          (LBS.fromStrict rsBody)
+      else
+        response HTTP.status204 headers mempty
+
+  RSPlan plan ->
+    Wai.responseLBS HTTP.status200 (contentTypeHeaders ctxApiRequest) $ LBS.fromStrict plan
+
+infoResponse :: Target -> SchemaCache -> Wai.Response
+infoResponse target sCache =
+  case target of
+    TargetIdent identifier ->
+      case HM.lookup identifier (dbTables sCache) of
+        Just tbl -> respondInfo $ allowH tbl
+        Nothing  -> Error.errorResponseFor $ Error.ApiRequestError ApiRequestTypes.NotFound
+    TargetProc pd _
+      | pdVolatility pd == Volatile -> respondInfo "OPTIONS,POST"
+      | otherwise                   -> respondInfo "OPTIONS,GET,HEAD,POST"
+    TargetDefaultSpec _             -> respondInfo "OPTIONS,GET,HEAD"
+  where
+    respondInfo allowHeader = Wai.responseLBS HTTP.status200 [allOrigins, (HTTP.hAllow, allowHeader)] mempty
+    allOrigins = ("Access-Control-Allow-Origin", "*")
+    allowH table =
+      let hasPK = not . null $ tablePKCols table in
+      BS.intercalate "," $
+          ["OPTIONS,GET,HEAD"] ++
+          ["POST" | tableInsertable table] ++
+          ["PUT" | tableInsertable table && tableUpdatable table && hasPK] ++
+          ["PATCH" | tableUpdatable table] ++
+          ["DELETE" | tableDeletable table]
+
+invokeResponse :: InvokeMethod -> ProcDescription -> ApiRequest -> ResultSet -> Wai.Response
+invokeResponse invMethod proc ctxApiRequest@ApiRequest{..} resultSet = case resultSet of
+  RSStandard {..} -> do
+    let
+      response = gucResponse rsGucStatus rsGucHeaders
+      (status, contentRange) =
+        RangeQuery.rangeStatusHeader iTopLevelRange rsQueryTotal rsTableTotal
+      rsOrErrBody = if status == HTTP.status416
+        then Error.errorPayload $ Error.ApiRequestError $ ApiRequestTypes.InvalidRange
+          $ ApiRequestTypes.OutOfBounds (show $ RangeQuery.rangeOffset iTopLevelRange) (maybe "0" show rsTableTotal)
+        else LBS.fromStrict rsBody
+      headers = [contentRange]
+
+    if Proc.procReturnsVoid proc then
+        response HTTP.status204 headers mempty
+      else
+        response status
+          (headers ++ contentTypeHeaders ctxApiRequest)
+          (if invMethod == InvHead then mempty else rsOrErrBody)
+
+  RSPlan plan ->
+    Wai.responseLBS HTTP.status200 (contentTypeHeaders ctxApiRequest) $ LBS.fromStrict plan
+
+openApiResponse :: Bool -> Maybe (TablesMap, ProcsMap, Maybe Text) -> AppConfig -> SchemaCache -> Schema -> Bool -> Wai.Response
+openApiResponse headersOnly body conf sCache schema negotiatedByProfile =
+  Wai.responseLBS HTTP.status200
+    (MediaType.toContentType MTOpenAPI : maybeToList (profileHeader schema negotiatedByProfile))
+    (maybe mempty (\(x, y, z) -> if headersOnly then mempty else OpenAPI.encode conf sCache x y z) body)
+
+-- | Response with headers and status overridden from GUCs.
+gucResponse
+  :: Maybe Text
+  -> Maybe BS.ByteString
+  -> HTTP.Status
+  -> [HTTP.Header]
+  -> LBS.ByteString
+  -> Wai.Response
+gucResponse rsGucStatus rsGucHeaders status headers body =
+  case (,) <$> decodeGucStatus rsGucStatus <*> decodeGucHeaders rsGucHeaders of
+    Left err -> Error.errorResponseFor err
+    Right (gucStatus, gucHeaders) ->
+      Wai.responseLBS (fromMaybe status gucStatus) (addHeadersIfNotIncluded headers (map unwrapGucHeader gucHeaders)) body
+
+decodeGucHeaders :: Maybe BS.ByteString -> Either Error.Error [GucHeader]
+decodeGucHeaders =
+  maybe (Right []) $ first (const Error.GucHeadersError) . JSON.eitherDecode . LBS.fromStrict
+
+decodeGucStatus :: Maybe Text -> Either Error.Error (Maybe HTTP.Status)
+decodeGucStatus =
+  maybe (Right Nothing) $ first (const Error.GucStatusError) . fmap (Just . toEnum . fst) . decimal
+
+contentTypeHeaders :: ApiRequest -> [HTTP.Header]
+contentTypeHeaders ApiRequest{..} =
+  MediaType.toContentType iAcceptMediaType : maybeToList (profileHeader iSchema iNegotiatedByProfile)
+
+profileHeader :: Schema -> Bool -> Maybe HTTP.Header
+profileHeader schema negotiatedByProfile =
+  if negotiatedByProfile
+    then Just $ (,) "Content-Profile" (toS schema)
+  else
+    Nothing
+
+addRetryHint :: Int -> Wai.Response -> Wai.Response
+addRetryHint delay response = do
+  let h = ("Retry-After", BS.pack $ show delay)
+  Wai.mapResponseHeaders (\hs -> if isServiceUnavailable response then h:hs else hs) response
+
+isServiceUnavailable :: Wai.Response -> Bool
+isServiceUnavailable response = Wai.responseStatus response == HTTP.status503
+
+optionalRollback :: AppConfig -> ApiRequest -> ExceptT Error.Error IO Wai.Response -> ExceptT Error.Error IO Wai.Response
+optionalRollback AppConfig{..} ApiRequest{..} resp = do
+  newRes <- catchError resp $ return . Error.errorResponseFor
+  return $ Wai.mapResponseHeaders preferenceApplied newRes
+  where
+    shouldCommit =
+      configDbTxAllowOverride && iPreferTransaction == Just Commit
+    shouldRollback =
+      configDbTxAllowOverride && iPreferTransaction == Just Rollback
+    preferenceApplied
+      | shouldCommit =
+          addHeadersIfNotIncluded
+            [toAppliedHeader Commit]
+      | shouldRollback =
+          addHeadersIfNotIncluded
+            [toAppliedHeader Rollback]
+      | otherwise =
+          identity
+
+-- | Add headers not already included to allow the user to override them instead of duplicating them
+addHeadersIfNotIncluded :: [HTTP.Header] -> [HTTP.Header] -> [HTTP.Header]
+addHeadersIfNotIncluded newHeaders initialHeaders =
+  filter (\(nk, _) -> isNothing $ find (\(ik, _) -> ik == nk) initialHeaders) newHeaders ++
+  initialHeaders
@@ -1,12 +1,12 @@
-module PostgREST.GucHeader
+module PostgREST.Response.GucHeader
  ( GucHeader
  , unwrapGucHeader
-  , addHeadersIfNotIncluded
  ) where

 import qualified Data.Aeson           as JSON
+import qualified Data.Aeson.Key       as K
+import qualified Data.Aeson.KeyMap    as KM
 import qualified Data.CaseInsensitive as CI
-import qualified Data.HashMap.Strict  as M

 import Network.HTTP.Types.Header (Header)

@@ -21,16 +21,10 @@ newtype GucHeader = GucHeader (CI.CI ByteString, ByteString)

 instance JSON.FromJSON GucHeader where
  parseJSON (JSON.Object o) =
-    case M.toList o of
-      [(k, JSON.String s)] -> pure $ GucHeader (CI.mk $ toUtf8 k, toUtf8 s)
+    case KM.toList o of
+      [(k, JSON.String s)] -> pure $ GucHeader (CI.mk $ toUtf8 $ K.toText k, toUtf8 s)
      _ -> mzero
  parseJSON _ = mzero

 unwrapGucHeader :: GucHeader -> Header
 unwrapGucHeader (GucHeader (k, v)) = (k, v)
-
-- | Add headers not already included to allow the user to override them instead of duplicating them
-addHeadersIfNotIncluded :: [Header] -> [Header] -> [Header]
-addHeadersIfNotIncluded newHeaders initialHeaders =
-  filter (\(nk, _) -> isNothing $ find (\(ik, _) -> ik == nk) initialHeaders) newHeaders ++
-  initialHeaders
@@ -3,14 +3,13 @@ Module      : PostgREST.OpenAPI
 Description : Generates the OpenAPI output
 -}
 {-# LANGUAGE LambdaCase      #-}
-{-# LANGUAGE NamedFieldPuns  #-}
 {-# LANGUAGE RecordWildCards #-}
-module PostgREST.OpenAPI (encode) where
+module PostgREST.Response.OpenAPI (encode) where

 import qualified Data.Aeson            as JSON
 import qualified Data.ByteString.Char8 as BS
 import qualified Data.ByteString.Lazy  as LBS
-import qualified Data.HashMap.Strict   as M
+import qualified Data.HashMap.Strict   as HM
 import qualified Data.HashSet.InsOrd   as Set
 import qualified Data.Text             as T
 import qualified Data.Text.Encoding    as T
@@ -27,86 +26,98 @@ import Data.Swagger

 import PostgREST.Config                   (AppConfig (..), Proxy (..),
                                           isMalformedProxyUri, toURI)
-import PostgREST.DbStructure              (DbStructure (..),
-                                           tableCols, tablePKCols)
-import PostgREST.DbStructure.Proc         (ProcDescription (..),
+import PostgREST.SchemaCache              (SchemaCache (..))
+import PostgREST.SchemaCache.Identifiers  (QualifiedIdentifier (..))
+import PostgREST.SchemaCache.Proc         (ProcDescription (..),
                                           ProcParam (..))
-import PostgREST.DbStructure.Relationship (Cardinality (..),
-                                           PrimaryKey (..),
-                                           Relationship (..))
-import PostgREST.DbStructure.Table        (Column (..), Table (..))
+import PostgREST.SchemaCache.Relationship (Cardinality (..),
+                                           Relationship (..),
+                                           RelationshipsMap)
+import PostgREST.SchemaCache.Table        (Column (..), Table (..),
+                                           TablesMap)
 import PostgREST.Version                  (docsVersion, prettyVersion)

-import PostgREST.ContentType
+import PostgREST.MediaType

 import Protolude hiding (Proxy, get)

-encode :: AppConfig -> DbStructure -> [Table] -> M.HashMap k [ProcDescription] -> Maybe Text -> LBS.ByteString
-encode conf dbStructure tables procs schemaDescription =
+encode :: AppConfig -> SchemaCache -> TablesMap -> HM.HashMap k [ProcDescription] -> Maybe Text -> LBS.ByteString
+encode conf sCache tables procs schemaDescription =
  JSON.encode $
    postgrestSpec
-      (dbRelationships dbStructure)
-      (concat $ M.elems procs)
-      (openApiTableInfo dbStructure <$> tables)
+      (dbRelationships sCache)
+      (concat $ HM.elems procs)
+      (snd <$> HM.toList tables)
      (proxyUri conf)
      schemaDescription
-      (dbPrimaryKeys dbStructure)
+      (configOpenApiSecurityActive conf)

-makeMimeList :: [ContentType] -> MimeList
+makeMimeList :: [MediaType] -> MimeList
 makeMimeList cs = MimeList $ fmap (fromString . BS.unpack . toMime) cs

-toSwaggerType :: Text -> SwaggerType t
-toSwaggerType "character varying" = SwaggerString
-toSwaggerType "character"         = SwaggerString
-toSwaggerType "text"              = SwaggerString
-toSwaggerType "boolean"           = SwaggerBoolean
-toSwaggerType "smallint"          = SwaggerInteger
-toSwaggerType "integer"           = SwaggerInteger
-toSwaggerType "bigint"            = SwaggerInteger
-toSwaggerType "numeric"           = SwaggerNumber
-toSwaggerType "real"              = SwaggerNumber
-toSwaggerType "double precision"  = SwaggerNumber
-toSwaggerType "ARRAY"             = SwaggerArray
-toSwaggerType _                   = SwaggerString
+toSwaggerType :: Text -> Maybe (SwaggerType t)
+toSwaggerType "character varying" = Just SwaggerString
+toSwaggerType "character"         = Just SwaggerString
+toSwaggerType "text"              = Just SwaggerString
+toSwaggerType "boolean"           = Just SwaggerBoolean
+toSwaggerType "smallint"          = Just SwaggerInteger
+toSwaggerType "integer"           = Just SwaggerInteger
+toSwaggerType "bigint"            = Just SwaggerInteger
+toSwaggerType "numeric"           = Just SwaggerNumber
+toSwaggerType "real"              = Just SwaggerNumber
+toSwaggerType "double precision"  = Just SwaggerNumber
+toSwaggerType "json"              = Nothing
+toSwaggerType "jsonb"             = Nothing
+toSwaggerType colType             = case T.takeEnd 2 colType of
+  "[]" -> Just SwaggerArray
+  _    -> Just SwaggerString
+
+makeSwaggerItemType :: Maybe (SwaggerType t) -> Text -> Maybe (Referenced Schema)
+makeSwaggerItemType itemType colType = case itemType of
+  Just SwaggerArray -> Just $ Inline (mempty & type_ .~ toSwaggerType (T.dropEnd 2 colType))
+  _                 -> Nothing

 parseDefault :: Text -> Text -> Text
 parseDefault colType colDefault =
  case toSwaggerType colType of
-    SwaggerString -> wrapInQuotations $ case T.stripSuffix ("::" <> colType) colDefault of
+    Just SwaggerString -> wrapInQuotations $ case T.stripSuffix ("::" <> colType) colDefault of
      Just def -> T.dropAround (=='\'')  def
      Nothing  -> colDefault
    _ -> colDefault
  where
    wrapInQuotations text = "\"" <> text <> "\""

-makeTableDef :: [Relationship] -> [PrimaryKey] -> (Table, [Column], [Text]) -> (Text, Schema)
-makeTableDef rels pks (t, cs, _) =
+makeTableDef :: RelationshipsMap -> Table -> (Text, Schema)
+makeTableDef rels t =
  let tn = tableName t in
      (tn, (mempty :: Schema)
        & description .~ tableDescription t
        & type_ ?~ SwaggerObject
-        & properties .~ fromList (fmap (makeProperty rels pks) cs)
-        & required .~ fmap colName (filter (not . colNullable) cs))
+        & properties .~ fromList (makeProperty t rels <$> tableColumns t)
+        & required .~ fmap colName (filter (not . colNullable) $ tableColumns t))

-makeProperty :: [Relationship] -> [PrimaryKey] -> Column -> (Text, Referenced Schema)
-makeProperty rels pks c = (colName c, Inline s)
+makeProperty :: Table -> RelationshipsMap -> Column -> (Text, Referenced Schema)
+makeProperty tbl rels col = (colName col, Inline s)
  where
-    e = if null $ colEnum c then Nothing else JSON.decode $ JSON.encode $ colEnum c
+    e = if null $ colEnum col then Nothing else JSON.decode $ JSON.encode $ colEnum col
    fk :: Maybe Text
    fk =
      let
+        searchedRels = fromMaybe mempty $ HM.lookup (QualifiedIdentifier (tableSchema tbl) (tableName tbl), tableSchema tbl) rels
+        -- Sorts the relationship list to get tables first
+        relsSortedByIsView = sortOn relFTableIsView [ r | r@Relationship{} <- searchedRels]
        -- Finds the relationship that has a single column foreign key
        rel = find (\case
-          Relationship{relColumns, relCardinality=M2O _} -> [c] == relColumns
-          _                                                 -> False
-          ) rels
-        fCol = colName <$> (headMay . relForeignColumns =<< rel)
-        fTbl = tableName . relForeignTable <$> rel
+          Relationship{relCardinality=(M2O _ relColumns)} -> [colName col] == (fst <$> relColumns)
+          _                                               -> False
+          ) relsSortedByIsView
+        fCol = (headMay . (\r -> snd <$> relColumns (relCardinality r)) =<< rel)
+        fTbl = qiName . relForeignTable <$> rel
        fTblCol = (,) <$> fTbl <*> fCol
      in
        (\(a, b) -> T.intercalate "" ["This is a Foreign Key to `", a, ".", b, "`.<fk table='", a, "' column='", b, "'/>"]) <$> fTblCol
    pk :: Bool
-    pk = any (\p -> pkTable p == colTable c && pkName p == colName c) pks
+    pk = colName col `elem` tablePKCols tbl
    n = catMaybes
      [ Just "Note:"
      , if pk then Just "This is a Primary Key.<pk/>" else Nothing
@@ -114,17 +125,19 @@ makeProperty rels pks c = (colName c, Inline s)
      ]
    d =
      if length n > 1 then
-        Just $ T.append (maybe "" (`T.append` "\n\n") $ colDescription c) (T.intercalate "\n" n)
+        Just $ T.append (maybe "" (`T.append` "\n\n") $ colDescription col) (T.intercalate "\n" n)
      else
-        colDescription c
+        colDescription col
+    pType = toSwaggerType (colType col)
    s =
      (mempty :: Schema)
-        & default_ .~ (JSON.decode . toUtf8Lazy . parseDefault (colType c) =<< colDefault c)
+        & default_ .~ (JSON.decode . toUtf8Lazy . parseDefault (colType col) =<< colDefault col)
        & description .~ d
        & enum_ .~ e
-        & format ?~ colType c
-        & maxLength .~ (fromIntegral <$> colMaxLen c)
-        & type_ ?~ toSwaggerType (colType c)
+        & format ?~ colType col
+        & maxLength .~ (fromIntegral <$> colMaxLen col)
+        & type_ .~ pType
+        & items .~ (SwaggerItemsObject <$> makeSwaggerItemType pType (colType col))

 makeProcSchema :: ProcDescription -> Schema
 makeProcSchema pd =
@@ -138,7 +151,8 @@ makeProcProperty :: ProcParam -> (Text, Referenced Schema)
 makeProcProperty (ProcParam n t _ _) = (n, Inline s)
  where
    s = (mempty :: Schema)
-          & type_ ?~ toSwaggerType t
+          & type_ .~ toSwaggerType t
+          & items .~ (SwaggerItemsObject <$> makeSwaggerItemType (toSwaggerType t) t)
          & format ?~ t

 makePreferParam :: [Text] -> Param
@@ -150,7 +164,15 @@ makePreferParam ts =
  & schema .~ ParamOther ((mempty :: ParamOtherSchema)
    & in_ .~ ParamHeader
    & type_ ?~ SwaggerString
-    & enum_ .~ JSON.decode (JSON.encode ts))
+    & enum_ .~ JSON.decode (JSON.encode $ foldl (<>) [] (val <$> ts)))
+  where
+    val :: Text -> [Text]
+    val = \case
+      "count"      -> ["count=none"]
+      "params"     -> ["params=single-object"]
+      "return"     -> ["return=representation", "return=minimal", "return=none"]
+      "resolution" -> ["resolution=ignore-duplicates", "resolution=merge-duplicates"]
+      _            -> []

 makeProcParam :: ProcDescription -> [Referenced Param]
 makeProcParam pd =
@@ -161,11 +183,13 @@ makeProcParam pd =
  , Ref $ Reference "preferParams"
  ]

-makeParamDefs :: [(Table, [Column], [Text])] -> [(Text, Param)]
+makeParamDefs :: [Table] -> [(Text, Param)]
 makeParamDefs ti =
-  [ ("preferParams", makePreferParam ["params=single-object"])
-  , ("preferReturn", makePreferParam ["return=representation", "return=minimal", "return=none"])
-  , ("preferCount", makePreferParam ["count=none"])
+  -- TODO: create Prefer for each method (GET, PATCH, etc.)
+  [ ("preferParams", makePreferParam ["params"])
+  , ("preferReturn", makePreferParam ["return"])
+  , ("preferCount", makePreferParam ["count"])
+  , ("preferPost", makePreferParam ["return", "resolution"])
  , ("select", (mempty :: Param)
      & name        .~ "select"
      & description ?~ "Filtering Columns"
@@ -217,8 +241,8 @@ makeParamDefs ti =
        & in_ .~ ParamQuery
        & type_ ?~ SwaggerString))
  ]
-  <> concat [ makeObjectBody (tableName t) : makeRowFilters (tableName t) cs
-            | (t, cs, _) <- ti
+  <> concat [ makeObjectBody (tableName t) : makeRowFilters (tableName t) (tableColumns t)
+            | t <- ti
            ]

 makeObjectBody :: Text -> (Text, Param)
@@ -243,8 +267,8 @@ makeRowFilter tn c =
 makeRowFilters :: Text -> [Column] -> [(Text, Param)]
 makeRowFilters tn = fmap (makeRowFilter tn)

-makePathItem :: (Table, [Column], [Text]) -> (FilePath, PathItem)
-makePathItem (t, cs, _) = ("/" ++ T.unpack tn, p $ tableInsertable t || tableUpdatable t || tableDeletable t)
+makePathItem :: Table -> (FilePath, PathItem)
+makePathItem t = ("/" ++ T.unpack tn, p $ tableInsertable t || tableUpdatable t || tableDeletable t)
  where
    -- Use first line of table description as summary; rest as description (if present)
    -- We strip leading newlines from description so that users can include a blank line between summary and description
@@ -265,7 +289,7 @@ makePathItem (t, cs, _) = ("/" ++ T.unpack tn, p $ tableInsertable t || tableUpd
        )
      )
    postOp = tOp
-      & parameters .~ fmap ref ["body." <> tn, "select", "preferReturn"]
+      & parameters .~ fmap ref ["body." <> tn, "select", "preferPost"]
      & at 201 ?~ "Created"
    patchOp = tOp
      & parameters .~ fmap ref (rs <> ["body." <> tn, "preferReturn"])
@@ -278,7 +302,7 @@ makePathItem (t, cs, _) = ("/" ++ T.unpack tn, p $ tableInsertable t || tableUpd
    p False = pr
    p True  = pw
    tn = tableName t
-    rs = [ T.intercalate "." ["rowFilter", tn, colName c ] | c <- cs ]
+    rs = [ T.intercalate "." ["rowFilter", tn, colName c ] | c <- tableColumns t ]
    ref = Ref . Reference

 makeProcPathItem :: ProcDescription -> (FilePath, PathItem)
@@ -293,7 +317,7 @@ makeProcPathItem pd = ("/rpc/" ++ toS (pdName pd), pe)
      & description .~ mfilter (/="") pDesc
      & parameters .~ makeProcParam pd
      & tags .~ Set.fromList ["(rpc) " <> pdName pd]
-      & produces ?~ makeMimeList [CTApplicationJSON, CTSingularJSON]
+      & produces ?~ makeMimeList [MTApplicationJSON, MTSingularJSON]
      & at 200 ?~ "OK"
    pe = (mempty :: PathItem) & post ?~ postOp

@@ -303,15 +327,23 @@ makeRootPathItem = ("/", p)
    getOp = (mempty :: Operation)
      & tags .~ Set.fromList ["Introspection"]
      & summary ?~ "OpenAPI description (this document)"
-      & produces ?~ makeMimeList [CTOpenAPI, CTApplicationJSON]
+      & produces ?~ makeMimeList [MTOpenAPI, MTApplicationJSON]
      & at 200 ?~ "OK"
    pr = (mempty :: PathItem) & get ?~ getOp
    p = pr

-makePathItems :: [ProcDescription] -> [(Table, [Column], [Text])] -> InsOrdHashMap FilePath PathItem
+makePathItems :: [ProcDescription] -> [Table] -> InsOrdHashMap FilePath PathItem
 makePathItems pds ti = fromList $ makeRootPathItem :
  fmap makePathItem ti ++ fmap makeProcPathItem pds

+makeSecurityDefinitions :: Text -> Bool -> SecurityDefinitions
+makeSecurityDefinitions secName allow
+  | allow = SecurityDefinitions (fromList [(secName, SecurityScheme secSchType secSchDescription)])
+  | otherwise    = mempty
+  where
+    secSchType = SecuritySchemeApiKey (ApiKeyParams "Authorization" ApiKeyHeader)
+    secSchDescription = Just "Add the token prepending \"Bearer \" (without quotes) to it"
+
 escapeHostName :: Text -> Text
 escapeHostName "*"  = "0.0.0.0"
 escapeHostName "*4" = "0.0.0.0"
@@ -320,8 +352,8 @@ escapeHostName "*6" = "0.0.0.0"
 escapeHostName "!6" = "0.0.0.0"
 escapeHostName h    = h

-postgrestSpec :: [Relationship] -> [ProcDescription] -> [(Table, [Column], [Text])] -> (Text, Text, Integer, Text) -> Maybe Text -> [PrimaryKey] -> Swagger
-postgrestSpec rels pds ti (s, h, p, b) sd pks = (mempty :: Swagger)
+postgrestSpec :: RelationshipsMap -> [ProcDescription] -> [Table] -> (Text, Text, Integer, Text) -> Maybe Text -> Bool -> Swagger
+postgrestSpec rels pds ti (s, h, p, b) sd allowSecurityDef = (mempty :: Swagger)
  & basePath ?~ T.unpack b
  & schemes ?~ [s']
  & info .~ ((mempty :: Info)
@@ -332,15 +364,18 @@ postgrestSpec rels pds ti (s, h, p, b) sd pks = (mempty :: Swagger)
    & description ?~ "PostgREST Documentation"
    & url .~ URL ("https://postgrest.org/en/" <> docsVersion <> "/api.html"))
  & host .~ h'
-  & definitions .~ fromList (makeTableDef rels pks <$> ti)
+  & definitions .~ fromList (makeTableDef rels <$> ti)
  & parameters .~ fromList (makeParamDefs ti)
  & paths .~ makePathItems pds ti
-  & produces .~ makeMimeList [CTApplicationJSON, CTSingularJSON, CTTextCSV]
-  & consumes .~ makeMimeList [CTApplicationJSON, CTSingularJSON, CTTextCSV]
+  & produces .~ makeMimeList [MTApplicationJSON, MTSingularJSON, MTTextCSV]
+  & consumes .~ makeMimeList [MTApplicationJSON, MTSingularJSON, MTTextCSV]
+  & securityDefinitions .~ makeSecurityDefinitions securityDefName allowSecurityDef
+  & security .~ [SecurityRequirement (fromList [(securityDefName, [])]) | allowSecurityDef]
    where
      s' = if s == "http" then Http else Https
      h' = Just $ Host (T.unpack $ escapeHostName h) (Just (fromInteger p))
      d = fromMaybe "This is a dynamic API generated by PostgREST" sd
+      securityDefName = "JWT"

 pickProxy :: Maybe Text -> Maybe Proxy
 pickProxy proxy
@@ -378,10 +413,3 @@ proxyUri AppConfig{..} =
      (proxyScheme, proxyHost, proxyPort, proxyPath)
    Nothing ->
      ("http", configServerHost, toInteger configServerPort, "/")
-
-openApiTableInfo :: DbStructure -> Table -> (Table, [Column], [Text])
-openApiTableInfo dbStructure table =
-  ( table
-  , tableCols dbStructure (tableSchema table) (tableName table)
-  , tablePKCols dbStructure (tableSchema table) (tableName table)
-  )
@@ -1,16 +1,18 @@
 {-# LANGUAGE DeriveAnyClass #-}
 {-# LANGUAGE DeriveGeneric  #-}

-module PostgREST.DbStructure.Identifiers
+module PostgREST.SchemaCache.Identifiers
  ( QualifiedIdentifier(..)
  , Schema
  , TableName
  , FieldName
+  , AccessSet
  , dumpQi
  , toQi
  ) where

 import qualified Data.Aeson as JSON
+import qualified Data.Set   as S
 import qualified Data.Text  as T

 import Protolude
@@ -40,3 +42,5 @@ toQi txt = case T.drop 1 <$> T.breakOn "." txt of
 type Schema = Text
 type TableName = Text
 type FieldName = Text
+
+type AccessSet = S.Set QualifiedIdentifier
@@ -1,7 +1,7 @@
 {-# LANGUAGE DeriveAnyClass #-}
 {-# LANGUAGE DeriveGeneric  #-}

-module PostgREST.DbStructure.Proc
+module PostgREST.SchemaCache.Proc
  ( PgType(..)
  , ProcDescription(..)
  , ProcParam(..)
@@ -10,13 +10,14 @@ module PostgREST.DbStructure.Proc
  , RetType(..)
  , procReturnsScalar
  , procReturnsSingle
+  , procReturnsVoid
  , procTableName
  ) where

 import qualified Data.Aeson          as JSON
-import qualified Data.HashMap.Strict as M
+import qualified Data.HashMap.Strict as HM

-import PostgREST.DbStructure.Identifiers (QualifiedIdentifier (..),
+import PostgREST.SchemaCache.Identifiers (QualifiedIdentifier (..),
                                          Schema, TableName)

 import Protolude
@@ -42,7 +43,7 @@ data ProcDescription = ProcDescription
  , pdName        :: Text
  , pdDescription :: Maybe Text
  , pdParams      :: [ProcParam]
-  , pdReturnType  :: RetType
+  , pdReturnType  :: Maybe RetType
  , pdVolatility  :: ProcVolatility
  , pdHasVariadic :: Bool
  }
@@ -65,21 +66,26 @@ instance Ord ProcDescription where

 -- | A map of all procs, all of which can be overloaded(one entry will have more than one ProcDescription).
 -- | It uses a HashMap for a faster lookup.
-type ProcsMap = M.HashMap QualifiedIdentifier [ProcDescription]
+type ProcsMap = HM.HashMap QualifiedIdentifier [ProcDescription]

 procReturnsScalar :: ProcDescription -> Bool
 procReturnsScalar proc = case proc of
-  ProcDescription{pdReturnType = (Single Scalar)} -> True
-  ProcDescription{pdReturnType = (SetOf Scalar)}  -> True
-  _                                               -> False
+  ProcDescription{pdReturnType = Just (Single Scalar)} -> True
+  ProcDescription{pdReturnType = Just (SetOf Scalar)}  -> True
+  _                                                    -> False

 procReturnsSingle :: ProcDescription -> Bool
 procReturnsSingle proc = case proc of
-  ProcDescription{pdReturnType = (Single _)} -> True
-  _                                          -> False
+  ProcDescription{pdReturnType = Just (Single _)} -> True
+  _                                               -> False
+
+procReturnsVoid :: ProcDescription -> Bool
+procReturnsVoid proc = case proc of
+  ProcDescription{pdReturnType = Nothing} -> True
+  _                                       -> False

 procTableName :: ProcDescription -> Maybe TableName
 procTableName proc = case pdReturnType proc of
-  SetOf  (Composite qi) -> Just $ qiName qi
-  Single (Composite qi) -> Just $ qiName qi
-  _                     -> Nothing
+  Just (SetOf  (Composite qi)) -> Just $ qiName qi
+  Just (Single (Composite qi)) -> Just $ qiName qi
+  _                            -> Nothing
@@ -0,0 +1,64 @@
+{-# LANGUAGE DeriveAnyClass #-}
+{-# LANGUAGE DeriveGeneric  #-}
+
+module PostgREST.SchemaCache.Relationship
+  ( Cardinality(..)
+  , Relationship(..)
+  , Junction(..)
+  , RelationshipsMap
+  ) where
+
+import qualified Data.Aeson          as JSON
+import qualified Data.HashMap.Strict as HM
+
+import PostgREST.SchemaCache.Identifiers (FieldName,
+                                          QualifiedIdentifier, Schema)
+
+import Protolude
+
+
+-- | Relationship between two tables.
+data Relationship = Relationship
+  { relTable        :: QualifiedIdentifier
+  , relForeignTable :: QualifiedIdentifier
+  , relIsSelf       :: Bool -- ^ Whether is a self relationship
+  , relCardinality  :: Cardinality
+  , relTableIsView  :: Bool
+  , relFTableIsView :: Bool
+  }
+  | ComputedRelationship
+  { relFunction     :: QualifiedIdentifier
+  , relTable        :: QualifiedIdentifier
+  , relForeignTable :: QualifiedIdentifier
+  , relToOne        :: Bool
+  , relIsSelf       :: Bool
+  }
+  deriving (Eq, Ord, Generic, JSON.ToJSON)
+
+-- | The relationship cardinality
+-- | https://en.wikipedia.org/wiki/Cardinality_(data_modeling)
+data Cardinality
+  = O2M {relCons :: FKConstraint, relColumns :: [(FieldName, FieldName)]}
+  -- ^ one-to-many
+  | M2O {relCons :: FKConstraint, relColumns :: [(FieldName, FieldName)]}
+  -- ^ many-to-one
+  | O2O {relCons :: FKConstraint, relColumns :: [(FieldName, FieldName)]}
+  -- ^ one-to-one, this is a refinement over M2O so operating on it is pretty much the same as M2O
+  | M2M Junction
+  -- ^ many-to-many
+  deriving (Eq, Ord, Generic, JSON.ToJSON)
+
+type FKConstraint = Text
+
+-- | Junction table on an M2M relationship
+data Junction = Junction
+  { junTable       :: QualifiedIdentifier
+  , junConstraint1 :: FKConstraint
+  , junConstraint2 :: FKConstraint
+  , junColsSource  :: [(FieldName, FieldName)]
+  , junColsTarget  :: [(FieldName, FieldName)]
+  }
+  deriving (Eq, Ord, Generic, JSON.ToJSON)
+
+-- | Key based on the source table and the foreign table schema
+type RelationshipsMap = HM.HashMap (QualifiedIdentifier, Schema)  [Relationship]
@@ -1,15 +1,16 @@
 {-# LANGUAGE DeriveAnyClass #-}
 {-# LANGUAGE DeriveGeneric  #-}

-module PostgREST.DbStructure.Table
+module PostgREST.SchemaCache.Table
  ( Column(..)
  , Table(..)
-  , tableQi
+  , TablesMap
  ) where

-import qualified Data.Aeson as JSON
+import qualified Data.Aeson          as JSON
+import qualified Data.HashMap.Strict as HM

-import PostgREST.DbStructure.Identifiers (FieldName,
+import PostgREST.SchemaCache.Identifiers (FieldName,
                                          QualifiedIdentifier (..),
                                          Schema, TableName)

@@ -20,22 +21,22 @@ data Table = Table
  { tableSchema      :: Schema
  , tableName        :: TableName
  , tableDescription :: Maybe Text
+     -- TODO Find a better way to separate tables and views
+   , tableIsView     :: Bool
    -- The following fields identify what can be done on the table/view, they're not related to the privileges granted to it
  , tableInsertable  :: Bool
  , tableUpdatable   :: Bool
  , tableDeletable   :: Bool
+  , tablePKCols      :: [FieldName]
+  , tableColumns     :: [Column]
  }
  deriving (Show, Ord, Generic, JSON.ToJSON)

 instance Eq Table where
  Table{tableSchema=s1,tableName=n1} == Table{tableSchema=s2,tableName=n2} = s1 == s2 && n1 == n2

-tableQi :: Table -> QualifiedIdentifier
-tableQi Table{tableSchema=s, tableName=n} = QualifiedIdentifier s n
-
 data Column = Column
-  { colTable       :: Table
-  , colName        :: FieldName
+  { colName        :: FieldName
  , colDescription :: Maybe Text
  , colNullable    :: Bool
  , colType        :: Text
@@ -43,13 +44,6 @@ data Column = Column
  , colDefault     :: Maybe Text
  , colEnum        :: [Text]
  }
-  deriving (Ord, Generic, JSON.ToJSON)
+  deriving (Eq, Show, Ord, Generic, JSON.ToJSON)

-instance Eq Column where
-  Column{colTable=t1,colName=n1} == Column{colTable=t2,colName=n2} = t1 == t2 && n1 == n2
-
-data PrimaryKey = PrimaryKey
-  { pkTable :: Table
-  , pkName  :: Text
-  }
-  deriving (Generic, JSON.ToJSON)
+type TablesMap = HM.HashMap QualifiedIdentifier Table
@@ -43,12 +43,11 @@ runAppWithSocket settings app socketFileMode socketFilePath =
 -- | Set signal handlers, only for systems with signals
 installSignalHandlers :: AppState.AppState -> IO ()
 installSignalHandlers appState = do
-  -- Releases the connection pool whenever the program is terminated,
-  -- see https://github.com/PostgREST/postgrest/issues/268
-  install Signals.sigINT $ AppState.releasePool appState
-  install Signals.sigTERM $ AppState.releasePool appState
+  let interrupt = throwTo (AppState.getMainThreadId appState) UserInterrupt
+  install Signals.sigINT interrupt
+  install Signals.sigTERM interrupt

-  -- The SIGUSR1 signal updates the internal 'DbStructure' by running
+  -- The SIGUSR1 signal updates the internal 'SchemaCache' by running
  -- 'connectionWorker' exactly as before.
  install Signals.sigUSR1 $ Workers.connectionWorker appState

@@ -30,10 +30,12 @@ prettyVersion =


 -- | Version number used in docs.
+-- Pre-release versions link to the latest docs
 -- Uses only the two first components of the version. Example: 'v1.1'
 docsVersion :: Text
-docsVersion =
-  "v" <> (T.intercalate "." . map show . take 2 $ versionBranch version)
+docsVersion
+  | isPreRelease = "latest"
+  | otherwise    =  "v" <> (T.intercalate "." . map show . take 2 $ versionBranch version)


 -- | Versions with four components (e.g., '1.1.1.1') are treated as pre-releases.
@@ -1,31 +1,38 @@
 {-# LANGUAGE LambdaCase      #-}
+{-# LANGUAGE NamedFieldPuns  #-}
 {-# LANGUAGE RecordWildCards #-}

 module PostgREST.Workers
  ( connectionWorker
  , reReadConfig
-  , listener
+  , runListener
+  , runAdmin
  ) where

 import qualified Data.Aeson                 as JSON
 import qualified Data.ByteString            as BS
 import qualified Data.ByteString.Lazy       as LBS
-import qualified Data.Text.Encoding         as T
+import qualified Data.Text                  as T
 import qualified Hasql.Notifications        as SQL
-import qualified Hasql.Pool                 as SQL
+import qualified Hasql.Session              as SQL
 import qualified Hasql.Transaction.Sessions as SQL
+import qualified Network.HTTP.Types.Status  as HTTP
+import qualified Network.Wai                as Wai
+import qualified Network.Wai.Handler.Warp   as Warp

 import Control.Retry    (RetryStatus, capDelay, exponentialBackoff,
                         retrying, rsPreviousDelay)
 import Hasql.Connection (acquire)

+import Network.Socket
+import Network.Socket.ByteString
+
 import PostgREST.AppState         (AppState)
 import PostgREST.Config           (AppConfig (..), readAppConfig)
 import PostgREST.Config.Database  (queryDbSettings, queryPgVersion)
 import PostgREST.Config.PgVersion (PgVersion (..), minimumPgVersion)
-import PostgREST.DbStructure      (queryDbStructure)
-import PostgREST.Error            (PgError (PgError), checkIsFatal,
-                                   errorPayload)
+import PostgREST.Error            (checkIsFatal)
+import PostgREST.SchemaCache      (querySchemaCache)

 import qualified PostgREST.AppState as AppState

@@ -46,35 +53,36 @@ data SCacheStatus
  | SCFatalFail

 -- | The purpose of this worker is to obtain a healthy connection to pg and an
-- up-to-date schema cache(DbStructure).  This method is meant to be called
+-- up-to-date schema cache(SchemaCache).  This method is meant to be called
 -- multiple times by the same thread, but does nothing if the previous
 -- invocation has not terminated. In all cases this method does not halt the
-- calling thread, the work is preformed in a separate thread.
+-- calling thread, the work is performed in a separate thread.
 --
 -- Background thread that does the following :
 --  1. Tries to connect to pg server and will keep trying until success.
 --  2. Checks if the pg version is supported and if it's not it kills the main
 --     program.
--  3. Obtains the dbStructure. If this fails, it goes back to 1.
+--  3. Obtains the sCache. If this fails, it goes back to 1.
 connectionWorker :: AppState -> IO ()
 connectionWorker appState = do
-  isWorkerOn <- AppState.getIsWorkerOn appState
+  runExclusively (AppState.getWorkerSem appState) work
  -- Prevents multiple workers to be running at the same time. Could happen on
  -- too many SIGUSR1s.
-  unless isWorkerOn $ do
-    AppState.putIsWorkerOn appState True
-    void $ forkIO work
  where
+    runExclusively mvar action = mask_ $ do
+      success <- tryPutMVar mvar ()
+      when success $ do
+        void $ forkIO $ action `finally` takeMVar mvar
    work = do
      AppConfig{..} <- AppState.getConfig appState
      AppState.logWithZTime appState "Attempting to connect to the database..."
-      connected <- connectionStatus appState
+      connected <- establishConnection appState
      case connected of
        FatalConnectionError reason ->
          -- Fatal error when connecting
          AppState.logWithZTime appState reason >> killThread (AppState.getMainThreadId appState)
        NotConnected ->
-          -- Unreachable because connectionStatus will keep trying to connect
+          -- Unreachable because establishConnection will keep trying to connect
          return ()
        Connected actualPgVersion -> do
          -- Procede with initialization
@@ -91,39 +99,38 @@ connectionWorker appState = do
              -- do nothing and proceed if the load was successful
              return ()
            SCOnRetry ->
+              -- retry reloading the schema cache
              work
            SCFatalFail ->
              -- die if our schema cache query has an error
              killThread $ AppState.getMainThreadId appState
-          AppState.putIsWorkerOn appState False

-- | Check if a connection from the pool allows access to the PostgreSQL
-- database.  If not, the pool connections are released and a new connection is
-- tried.  Releasing the pool is key for rapid recovery. Otherwise, the pool
+-- | Repeatedly flush the pool, and check if a connection from the
+-- pool allows access to the PostgreSQL database.
+--
+-- Releasing the pool is key for rapid recovery. Otherwise, the pool
 -- timeout would have to be reached for new healthy connections to be acquired.
 -- Which might not happen if the server is busy with requests. No idle
 -- connection, no pool timeout.
 --
 -- The connection tries are capped, but if the connection times out no error is
 -- thrown, just 'False' is returned.
-connectionStatus :: AppState -> IO ConnectionStatus
-connectionStatus appState =
+establishConnection :: AppState -> IO ConnectionStatus
+establishConnection appState =
  retrying retrySettings shouldRetry $
-    const $ SQL.release pool >> getConnectionStatus
+    const $ AppState.flushPool appState >> getConnectionStatus
  where
-    pool = AppState.getPool appState
    retrySettings = capDelay delayMicroseconds $ exponentialBackoff backoffMicroseconds
    delayMicroseconds = 32000000 -- 32 seconds
    backoffMicroseconds = 1000000 -- 1 second

    getConnectionStatus :: IO ConnectionStatus
    getConnectionStatus = do
-      pgVersion <- SQL.use pool queryPgVersion
+      pgVersion <- AppState.usePool appState queryPgVersion
      case pgVersion of
        Left e -> do
-          let err = PgError False e
-          AppState.logWithZTime appState . T.decodeUtf8 . LBS.toStrict $ errorPayload err
-          case checkIsFatal err of
+          AppState.logPgrstError appState e
+          case checkIsFatal e of
            Just reason ->
              return $ FatalConnectionError reason
            Nothing ->
@@ -148,38 +155,39 @@ connectionStatus appState =
      when itShould $ AppState.putRetryNextIn appState delay
      return itShould

-- | Load the DbStructure by using a connection from the pool.
+-- | Load the SchemaCache by using a connection from the pool.
 loadSchemaCache :: AppState -> IO SCacheStatus
 loadSchemaCache appState = do
  AppConfig{..} <- AppState.getConfig appState
-  actualPgVersion <- AppState.getPgVersion appState
  result <-
    let transaction = if configDbPreparedStatements then SQL.transaction else SQL.unpreparedTransaction in
-    SQL.use (AppState.getPool appState) . transaction SQL.ReadCommitted SQL.Read $
-      queryDbStructure (toList configDbSchemas) configDbExtraSearchPath actualPgVersion configDbPreparedStatements
+    AppState.usePool appState . transaction SQL.ReadCommitted SQL.Read $
+      querySchemaCache (toList configDbSchemas) configDbExtraSearchPath configDbPreparedStatements
  case result of
    Left e -> do
-      let
-        err = PgError False e
-        putErr = AppState.logWithZTime appState . T.decodeUtf8 . LBS.toStrict $ errorPayload err
-      case checkIsFatal err of
+      case checkIsFatal e of
        Just hint -> do
          AppState.logWithZTime appState "A fatal error ocurred when loading the schema cache"
-          putErr
+          AppState.logPgrstError appState e
          AppState.logWithZTime appState hint
          return SCFatalFail
        Nothing -> do
+          AppState.putSchemaCache appState Nothing
          AppState.logWithZTime appState "An error ocurred when loading the schema cache"
-          putErr
+          AppState.logPgrstError appState e
          return SCOnRetry

-    Right dbStructure -> do
-      AppState.putDbStructure appState dbStructure
+    Right sCache -> do
+      AppState.putSchemaCache appState (Just sCache)
      when (isJust configDbRootSpec) .
-        AppState.putJsonDbS appState . LBS.toStrict $ JSON.encode dbStructure
+        AppState.putJsonDbS appState . LBS.toStrict $ JSON.encode sCache
      AppState.logWithZTime appState "Schema cache loaded"
      return SCLoaded

+runListener :: AppConfig -> AppState -> IO ()
+runListener AppConfig{configDbChannelEnabled} appState =
+  when configDbChannelEnabled $ listener appState
+
 -- | Starts a dedicated pg connection to LISTEN for notifications.  When a
 -- NOTIFY <db-channel> - with an empty payload - is done, it refills the schema
 -- cache.  It uses the connectionWorker in case the LISTEN connection dies.
@@ -200,6 +208,7 @@ listener appState = do
    case dbOrError of
      Right db -> do
        AppState.logWithZTime appState $ "Listening for notifications on the " <> dbChannel <> " channel"
+        AppState.putIsListenerOn appState True
        SQL.listen db $ SQL.toPgIdentifier dbChannel
        SQL.waitForNotifications handleNotification db
      _ ->
@@ -208,22 +217,22 @@ listener appState = do
    handleFinally dbChannel _ = do
      -- if the thread dies, we try to recover
      AppState.logWithZTime appState $ "Retrying listening for notifications on the " <> dbChannel <> " channel.."
+      AppState.putIsListenerOn appState False
      -- assume the pool connection was also lost, call the connection worker
      connectionWorker appState
      -- retry the listener
      listener appState

    handleNotification _ msg
-      | BS.null msg            = scLoader -- reload the schema cache
-      | msg == "reload schema" = scLoader -- reload the schema cache
-      | msg == "reload config" = reReadConfig False appState -- reload the config
+      | BS.null msg            = cacheReloader
+      | msg == "reload schema" = cacheReloader
+      | msg == "reload config" = reReadConfig False appState
      | otherwise              = pure () -- Do nothing if anything else than an empty message is sent

-    scLoader =
-      -- It's not necessary to check the loadSchemaCache success
-      -- here. If the connection drops, the thread will die and
-      -- proceed to recover.
-      void $ loadSchemaCache appState
+    cacheReloader =
+      -- reloads the schema cache + restarts pool connections
+      -- it's necessary to restart the pg connections because they cache the pg catalog(see #2620)
+      connectionWorker appState

 -- | Re-reads the config plus config options from the db
 reReadConfig :: Bool -> AppState -> IO ()
@@ -231,21 +240,18 @@ reReadConfig startingUp appState = do
  AppConfig{..} <- AppState.getConfig appState
  dbSettings <-
    if configDbConfig then do
-      qDbSettings <- queryDbSettings (AppState.getPool appState) configDbPreparedStatements
+      qDbSettings <- AppState.usePool appState $ queryDbSettings configDbPreparedStatements
      case qDbSettings of
        Left e -> do
-          let
-            err = PgError False e
-            putErr = AppState.logWithZTime appState . T.decodeUtf8 . LBS.toStrict $ errorPayload err
          AppState.logWithZTime appState
            "An error ocurred when trying to query database settings for the config parameters"
-          case checkIsFatal err of
+          case checkIsFatal e of
            Just hint -> do
-              putErr
+              AppState.logPgrstError appState e
              AppState.logWithZTime appState hint
              killThread (AppState.getMainThreadId appState)
            Nothing -> do
-              AppState.logWithZTime appState $ show e
+              AppState.logPgrstError appState e
          pure []
        Right x -> pure x
    else
@@ -255,10 +261,75 @@ reReadConfig startingUp appState = do
      if startingUp then
        panic err -- die on invalid config if the program is starting up
      else
-        AppState.logWithZTime appState $ "Failed re-loading config: " <> err
+        AppState.logWithZTime appState $ "Failed reloading config: " <> err
    Right newConf -> do
      AppState.putConfig appState newConf
      if startingUp then
        pass
      else
-        AppState.logWithZTime appState "Config re-loaded"
+        AppState.logWithZTime appState "Config reloaded"
+
+runAdmin :: AppConfig -> AppState -> Warp.Settings -> IO ()
+runAdmin conf@AppConfig{configAdminServerPort} appState settings =
+  whenJust configAdminServerPort $ \adminPort -> do
+    AppState.logWithZTime appState $ "Admin server listening on port " <> show adminPort
+    void . forkIO $ Warp.runSettings (settings & Warp.setPort adminPort) adminApp
+  where
+    whenJust :: Applicative m => Maybe a -> (a -> m ()) -> m ()
+    whenJust mg f = maybe (pure ()) f mg
+    adminApp = admin appState conf
+
+-- | PostgREST admin application
+admin :: AppState.AppState -> AppConfig -> Wai.Application
+admin appState appConfig req respond  = do
+  isMainAppReachable  <- any isRight <$> reachMainApp appConfig
+  isSchemaCacheLoaded <- isJust <$> AppState.getSchemaCache appState
+  isConnectionUp      <-
+    if configDbChannelEnabled appConfig
+      then AppState.getIsListenerOn appState
+      else isRight <$> AppState.usePool appState (SQL.sql "SELECT 1")
+
+  case Wai.pathInfo req of
+    ["ready"] ->
+      respond $ Wai.responseLBS (if isMainAppReachable && isConnectionUp && isSchemaCacheLoaded then HTTP.status200 else HTTP.status503) [] mempty
+    ["live"] ->
+      respond $ Wai.responseLBS (if isMainAppReachable then HTTP.status200 else HTTP.status503) [] mempty
+    _ ->
+      respond $ Wai.responseLBS HTTP.status404 [] mempty
+
+-- Try to connect to the main app socket
+-- Note that it doesn't even send a valid HTTP request, we just want to check that the main app is accepting connections
+-- The code for resolving the "*4", "!4", "*6", "!6", "*" special values is taken from
+-- https://hackage.haskell.org/package/streaming-commons-0.2.2.4/docs/src/Data.Streaming.Network.html#bindPortGenEx
+reachMainApp :: AppConfig -> IO [Either IOException ()]
+reachMainApp AppConfig{..} =
+  case configServerUnixSocket of
+    Just path ->  do
+      sock <- socket AF_UNIX Stream 0
+      (:[]) <$> try (do
+        connect sock $ SockAddrUnix path
+        withSocketsDo $ bracket (pure sock) close sendEmpty)
+    Nothing -> do
+      let
+        host | configServerHost `elem` ["*4", "!4", "*6", "!6", "*"] = Nothing
+             | otherwise                                             = Just configServerHost
+        filterAddrs xs =
+          case configServerHost of
+              "*4" -> ipv4Addrs xs ++ ipv6Addrs xs
+              "!4" -> ipv4Addrs xs
+              "*6" -> ipv6Addrs xs ++ ipv4Addrs xs
+              "!6" -> ipv6Addrs xs
+              _    -> xs
+        ipv4Addrs = filter ((/=) AF_INET6 . addrFamily)
+        ipv6Addrs = filter ((==) AF_INET6 . addrFamily)
+
+      addrs <- getAddrInfo (Just $ defaultHints { addrSocketType = Stream }) (T.unpack <$> host) (Just . show $ configServerPort)
+      tryAddr `traverse` filterAddrs addrs
+  where
+    sendEmpty sock = void $ send sock mempty
+    tryAddr :: AddrInfo -> IO (Either IOException ())
+    tryAddr addr = do
+      sock <- socket (addrFamily addr) (addrSocketType addr) (addrProtocol addr)
+      try $ do
+        connect sock $ addrAddress addr
+        withSocketsDo $ bracket (pure sock) close sendEmpty
@@ -1,4 +1,4 @@
-resolver: lts-18.14 # 2021-10-24, GHC 8.10.7
+resolver: lts-20.6 # 2023-01-09, GHC 9.2.5

 nix:
  packages:
@@ -10,6 +10,7 @@ nix:
  pure: false

 extra-deps:
-  - hasql-dynamic-statements-0.3.1@sha256:c3a2c89c4a8b3711368dbd33f0ccfe46a493faa7efc2c85d3e354c56a01dfc48,2673
-  - hasql-implicits-0.1.0.2@sha256:5d54e09cb779a209681b139fb3cc726bae75134557932156340cc0a56dd834a8,1361
-  - ptr-0.16.8.1@sha256:525219ec5f5da5c699725f7efcef91b00a7d44120fc019878b85c09440bf51d6,2686
+  - git: https://github.com/PostgREST/postgresql-libpq.git
+    commit: 890a0a16cf57dd401420fdc6c7d576fb696003bc
+  - hasql-notifications-0.2.0.4
+  - hasql-pool-0.9
@@ -5,29 +5,33 @@

 packages:
 - completed:
-    hackage: hasql-dynamic-statements-0.3.1@sha256:c3a2c89c4a8b3711368dbd33f0ccfe46a493faa7efc2c85d3e354c56a01dfc48,2673
+    commit: 890a0a16cf57dd401420fdc6c7d576fb696003bc
+    git: https://github.com/PostgREST/postgresql-libpq.git
+    name: postgresql-libpq
    pantry-tree:
-      size: 641
-      sha256: b1b9a6a26ec765e5fe29f9a670a5c9ec7067ea00dee8491f0819284ff0201b6f
+      sha256: 074668b9669b9c49f3c522c8af5c608799a1965e203c463b188b2632995beac2
+      size: 1414
+    version: 0.9.4.3
  original:
-    hackage: hasql-dynamic-statements-0.3.1@sha256:c3a2c89c4a8b3711368dbd33f0ccfe46a493faa7efc2c85d3e354c56a01dfc48,2673
+    commit: 890a0a16cf57dd401420fdc6c7d576fb696003bc
+    git: https://github.com/PostgREST/postgresql-libpq.git
 - completed:
-    hackage: hasql-implicits-0.1.0.2@sha256:5d54e09cb779a209681b139fb3cc726bae75134557932156340cc0a56dd834a8,1361
+    hackage: hasql-notifications-0.2.0.4@sha256:9a09fa9b97feadd9492c8bd8bc6b9cffe0513510102f08374b0c45ecd479ed67,2028
    pantry-tree:
-      size: 310
-      sha256: 2f00d1467d0e226b966c2cd7bac433c8948e2f7bbdf8a44936029f66fc20b5f3
+      sha256: 56f9e240728e7a65711dde45fa2e2075b914e32cd370424aaa4572392378a60e
+      size: 452
  original:
-    hackage: hasql-implicits-0.1.0.2@sha256:5d54e09cb779a209681b139fb3cc726bae75134557932156340cc0a56dd834a8,1361
+    hackage: hasql-notifications-0.2.0.4
 - completed:
-    hackage: ptr-0.16.8.1@sha256:525219ec5f5da5c699725f7efcef91b00a7d44120fc019878b85c09440bf51d6,2686
+    hackage: hasql-pool-0.9@sha256:db7a37f6b3a922c37adc3c7ced47a7c10786d1f171e47a735a6e812a587ba44c,2111
    pantry-tree:
-      size: 1089
-      sha256: d2b8440a738719ef8430ec38fe33b129e3940e4ccf2c016a727a1110a43656bb
+      sha256: 49b1181d28c6f5317e794671c2dae155754b834bdcfa30f7e5dbad28e4cf0249
+      size: 346
  original:
-    hackage: ptr-0.16.8.1@sha256:525219ec5f5da5c699725f7efcef91b00a7d44120fc019878b85c09440bf51d6,2686
+    hackage: hasql-pool-0.9
 snapshots:
 - completed:
-    size: 586069
-    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/18/14.yaml
-    sha256: 87842ecbaa8ca9cee59a7e6be52369dbed82ed075cb4e0d152614a627e8fd488
-  original: lts-18.14
+    sha256: 4905c93319aa94aa53da8f41d614d7bacdbfe6c63a8c6132d32e6e62f24a9af4
+    size: 649315
+    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/20/6.yaml
+  original: lts-20.6
@@ -1,74 +0,0 @@
-module Feature.CorsSpec where
-
-- {{{ Imports
-import qualified Data.ByteString.Lazy as BL
-
-import Network.Wai      (Application)
-import Network.Wai.Test (SResponse (simpleBody, simpleHeaders))
-
-import Network.HTTP.Types
-import Test.Hspec
-import Test.Hspec.Wai
-
-import Protolude
-import SpecHelper
-- }}}
-
-spec :: SpecWith ((), Application)
-spec =
-  describe "CORS" $ do
-    let preflightHeaders = [
-          ("Accept", "*/*"),
-          ("Origin", "http://example.com"),
-          ("Access-Control-Request-Method", "POST"),
-          ("Access-Control-Request-Headers", "Foo,Bar") ]
-    let normalCors = [
-          ("Host", "localhost:3000"),
-          ("User-Agent", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:32.0) Gecko/20100101 Firefox/32.0"),
-          ("Origin", "http://localhost:8000"),
-          ("Accept", "text/csv, */*; q=0.01"),
-          ("Accept-Language", "en-US,en;q=0.5"),
-          ("Accept-Encoding", "gzip, deflate"),
-          ("Referer", "http://localhost:8000/"),
-          ("Connection", "keep-alive") ]
-
-    describe "preflight request" $ do
-      it "replies naively and permissively to preflight request" $ do
-        r <- request methodOptions "/items" preflightHeaders ""
-        liftIO $ do
-          let respHeaders = simpleHeaders r
-          respHeaders `shouldSatisfy` matchHeader
-            "Access-Control-Allow-Origin"
-            "http://example.com"
-          respHeaders `shouldSatisfy` matchHeader
-            "Access-Control-Allow-Credentials"
-            "true"
-          respHeaders `shouldSatisfy` matchHeader
-            "Access-Control-Allow-Methods"
-            "GET, POST, PATCH, PUT, DELETE, OPTIONS, HEAD"
-          respHeaders `shouldSatisfy` matchHeader
-            "Access-Control-Allow-Headers"
-            "Authentication, Foo, Bar, Accept, Accept-Language, Content-Language"
-          respHeaders `shouldSatisfy` matchHeader
-            "Access-Control-Max-Age"
-            "86400"
-
-      it "suppresses body in response" $ do
-        r <- request methodOptions "/" preflightHeaders ""
-        liftIO $ simpleBody r `shouldBe` ""
-
-    describe "regular request" $
-      it "exposes necesssary response headers" $ do
-        r <- request methodGet "/items" [("Origin", "http://example.com")] ""
-        liftIO $ simpleHeaders r `shouldSatisfy` matchHeader
-          "Access-Control-Expose-Headers"
-          "Content-Encoding, Content-Location, Content-Range, Content-Type, \
-            \Date, Location, Server, Transfer-Encoding, Range-Unit"
-
-    describe "postflight request" $
-      it "allows INFO body through even with CORS request headers present" $ do
-        r <- request methodOptions "/items" normalCors ""
-        liftIO $ do
-          simpleHeaders r `shouldSatisfy` matchHeader
-            "Access-Control-Allow-Origin" "\\*"
-          simpleBody r `shouldSatisfy` BL.null
@@ -1,92 +0,0 @@
-module Feature.DeleteSpec where
-
-import Network.Wai (Application)
-
-import Network.HTTP.Types
-import Test.Hspec
-import Test.Hspec.Wai
-import Test.Hspec.Wai.JSON
-
-import Protolude hiding (get)
-
-spec :: SpecWith ((), Application)
-spec =
-  describe "Deleting" $ do
-    context "existing record" $ do
-      it "succeeds with 204 and deletion count" $
-        request methodDelete "/items?id=eq.1" [] ""
-          `shouldRespondWith` ""
-          { matchStatus  = 204
-          , matchHeaders = ["Content-Range" <:> "*/*"]
-          }
-
-      it "returns the deleted item and count if requested" $
-        request methodDelete "/items?id=eq.2" [("Prefer", "return=representation"), ("Prefer", "count=exact")] ""
-          `shouldRespondWith` [json|[{"id":2}]|]
-          { matchStatus  = 200
-          , matchHeaders = ["Content-Range" <:> "*/1"]
-          }
-
-      it "ignores ?select= when return not set or return=minimal" $ do
-        request methodDelete "/items?id=eq.3&select=id" [] ""
-          `shouldRespondWith` ""
-          { matchStatus  = 204
-          , matchHeaders = ["Content-Range" <:> "*/*"]
-          }
-        request methodDelete "/items?id=eq.3&select=id" [("Prefer", "return=minimal")] ""
-          `shouldRespondWith` ""
-          { matchStatus  = 204
-          , matchHeaders = ["Content-Range" <:> "*/*"]
-          }
-
-      it "returns the deleted item and shapes the response" $
-        request methodDelete "/complex_items?id=eq.2&select=id,name" [("Prefer", "return=representation")] ""
-          `shouldRespondWith` [json|[{"id":2,"name":"Two"}]|]
-          { matchStatus  = 200
-          , matchHeaders = ["Content-Range" <:> "*/*"]
-          }
-
-      it "can rename and cast the selected columns" $
-        request methodDelete "/complex_items?id=eq.3&select=ciId:id::text,ciName:name" [("Prefer", "return=representation")] ""
-          `shouldRespondWith` [json|[{"ciId":"3","ciName":"Three"}]|]
-
-      it "can embed (parent) entities" $
-        request methodDelete "/tasks?id=eq.8&select=id,name,project:projects(id)" [("Prefer", "return=representation")] ""
-          `shouldRespondWith` [json|[{"id":8,"name":"Code OSX","project":{"id":4}}]|]
-          { matchStatus  = 200
-          , matchHeaders = ["Content-Range" <:> "*/*"]
-          }
-
-    context "known route, no records matched" $
-      it "includes [] body if return=rep" $
-        request methodDelete "/items?id=eq.101"
-          [("Prefer", "return=representation")] ""
-          `shouldRespondWith` "[]"
-          { matchStatus  = 200
-          , matchHeaders = ["Content-Range" <:> "*/*"]
-          }
-
-    context "totally unknown route" $
-      it "fails with 404" $
-        request methodDelete "/foozle?id=eq.101" [] "" `shouldRespondWith` 404
-
-    context "table with limited privileges" $ do
-      it "fails deleting the row when return=representation and selecting all the columns" $
-        request methodDelete "/app_users?id=eq.1" [("Prefer", "return=representation")] mempty
-            `shouldRespondWith` 401
-
-      it "succeeds deleting the row when return=representation and selecting only the privileged columns" $
-        request methodDelete "/app_users?id=eq.1&select=id,email" [("Prefer", "return=representation")]
-          [json| { "password": "passxyz" } |]
-            `shouldRespondWith` [json|[ { "id": 1, "email": "test@123.com" } ]|]
-            { matchStatus  = 200
-            , matchHeaders = ["Content-Range" <:> "*/*"]
-            }
-
-      it "suceeds deleting the row with no explicit select when using return=minimal" $
-        request methodDelete "/app_users?id=eq.2" [("Prefer", "return=minimal")] mempty
-            `shouldRespondWith` 204
-
-      it "suceeds deleting the row with no explicit select by default" $
-        request methodDelete "/app_users?id=eq.3" [] mempty
-            `shouldRespondWith` 204
@@ -1,31 +0,0 @@
-module Feature.NoJwtSpec where
-
-- {{{ Imports
-
-import Network.Wai (Application)
-
-import Network.HTTP.Types
-import Test.Hspec
-import Test.Hspec.Wai
-import Test.Hspec.Wai.JSON
-
-import Protolude
-import SpecHelper
-- }}}
-
-spec :: SpecWith ((), Application)
-spec = describe "server started without JWT secret" $ do
-
-  -- this test will stop working 9999999999s after the UNIX EPOCH
-  it "responds with error on attempted auth" $ do
-    let auth = authHeaderJWT "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjk5OTk5OTk5OTksInJvbGUiOiJwb3N0Z3Jlc3RfdGVzdF9hdXRob3IiLCJpZCI6Impkb2UifQ.Dpss-QoLYjec5OTsOaAc3FNVsSjA89wACoV-0ra3ClA"
-    request methodGet "/authors_only" [auth] ""
-      `shouldRespondWith`
-      [json|{"message":"Server lacks JWT secret"}|]
-      { matchStatus  = 500
-      , matchHeaders = [ matchContentTypeJson ]
-      }
-
-  it "behaves normally when user does not attempt auth" $
-    request methodGet "/items" [] ""
-      `shouldRespondWith` 200
@@ -1,17 +0,0 @@
-module Feature.NonexistentSchemaSpec where
-
-import Network.Wai (Application)
-
-import Test.Hspec
-import Test.Hspec.Wai
-
-import Protolude hiding (get)
-
-spec :: SpecWith ((), Application)
-spec =
-  describe "Non existent api schema" $ do
-    it "succeeds when requesting root path" $
-      get "/" `shouldRespondWith` 200
-
-    it "gives 404 when requesting a nonexistent table in this nonexistent schema" $
-      get "/nonexistent_table" `shouldRespondWith` 404
@@ -1,69 +0,0 @@
-module Feature.QueryLimitedSpec where
-
-import Network.Wai (Application)
-
-import Network.HTTP.Types
-import Test.Hspec
-import Test.Hspec.Wai
-import Test.Hspec.Wai.JSON
-
-import Protolude  hiding (get)
-import SpecHelper
-
-spec :: SpecWith ((), Application)
-spec =
-  describe "Requesting many items with server limits(max-rows) enabled" $ do
-    it "restricts results" $
-      get "/items?order=id"
-        `shouldRespondWith`
-          [json| [{"id":1},{"id":2}] |]
-          { matchHeaders = ["Content-Range" <:> "0-1/*"] }
-
-    it "respects additional client limiting" $ do
-      request methodGet  "/items"
-          (rangeHdrs $ ByteRangeFromTo 0 0)
-          ""
-        `shouldRespondWith`
-          [json| [{"id":1}] |]
-          { matchHeaders = ["Content-Range" <:> "0-0/*"] }
-
-    it "works on all levels" $
-      get "/users?select=id,tasks(id)&order=id.asc&tasks.order=id.asc"
-        `shouldRespondWith`
-          [json|[{"id":1,"tasks":[{"id":1},{"id":2}]},{"id":2,"tasks":[{"id":5},{"id":6}]}]|]
-          { matchHeaders = ["Content-Range" <:> "0-1/*"] }
-
-    it "succeeds in getting parent embeds despite the limit, see #647" $
-      get "/tasks?select=id,project:projects(id)&id=gt.5"
-        `shouldRespondWith`
-          [json|[{"id":6,"project":{"id":3}},{"id":7,"project":{"id":4}}]|]
-          { matchHeaders = ["Content-Range" <:> "0-1/*"] }
-
-    it "can offset the parent embed, being consistent with the other embed types" $
-      get "/tasks?select=id,project:projects(id)&id=gt.5&project.offset=1"
-        `shouldRespondWith`
-          [json|[{"id":6,"project":null}, {"id":7,"project":null}]|]
-          { matchHeaders = ["Content-Range" <:> "0-1/*"] }
-
-    context "count=estimated" $ do
-      it "uses the query planner guess when query rows > maxRows" $
-        request methodHead "/getallprojects_view" [("Prefer", "count=estimated")] ""
-          `shouldRespondWith`
-            ""
-            { matchStatus  = 206
-            , matchHeaders = ["Content-Range" <:> "0-1/2019"]
-            }
-
-      it "gives exact count when query rows <= maxRows" $
-        request methodHead "/getallprojects_view?id=lt.3" [("Prefer", "count=estimated")] ""
-          `shouldRespondWith`
-            ""
-            { matchHeaders = ["Content-Range" <:> "0-1/2"] }
-
-      it "only uses the query planner guess if it's indeed greater than the exact count" $
-        request methodHead "/get_projects_above_view" [("Prefer", "count=estimated")] ""
-          `shouldRespondWith`
-            ""
-            { matchStatus  = 206
-            , matchHeaders = ["Content-Range" <:> "0-1/3"]
-            }
--- a/Show More
+++ b/Show More