I'm not sure whether that's Lix specific, but when I enter nix-shell, I
get quite a long TMPDIR, which results in all postgrest-with-pg-XX
scripts failing, because the unix socket path is too long. If TMPDIR was
not set, mktemp would fall back to /tmp, so we can just do that in any
case, which guarantees a short path in every case.
This adds a new log line that shows each schema cache query time individually, only on
`log-level=debug`. Like so:
```
$ PGRST_LOG_LEVEL=debug postgrest-with-pg-17 -f test/spec/fixtures/load.sql postgrest-run
....
10/Apr/2026:21:48:45 -0500: Schema cache queried in 192.2 milliseconds
10/Apr/2026:21:48:45 -0500: tables: 72.027 ms, keydeps: 20.118 ms, rels: 6.189 ms, funcs: 35.010 ms, comprels: 4.319 ms, dreps: 1.614 ms, mhandlers: 7.419 ms, tzones: 43.025 ms
```
This helps debug specific schema cache queries being slow like on
https://github.com/PostgREST/postgrest/issues/4613#issuecomment-4210191065 and
https://github.com/PostgREST/postgrest/issues/3046#issuecomment-3469059948.
It also closes https://github.com/PostgREST/postgrest/issues/3215,
which main motivation was to find out which query is slow.
Implementation details
---------------------
To time each query inside a transaction in pure SQL, we do:
```sql
-- start timer
select set_config('pgrst.tmp_x', clock_timestamp()::text, false);
-- run the query
select <query>
-- end timer
select set_config('pgrst.tmp_x', (clock_timestamp() - current_setting('pgrst.tmp_x', false)::timestamptz)::text, false);
-- .... repeated for every query
-- at the end we capture all the timings with
select extract('milliseconds' from current_setting('pgrst.tmp_x', false)::interval), extract(..;
```
Considerations
--------------
Only added this on `log-level=debug` because while the queries are fast
and the data is valuable, it triples the amount of queries we run during schema cache refresh,
which could be troublesome on slow networks. It's possible to reduce the
amount of queries by starting and stopping timers in one statement, but
this would still double the amount of queries and makes the code messy,
doesn't seem worth it.
Also it would pollute pg_stat_statements, it's only required to debug certain
extreme cases anyway.
retryingSchemaCacheLoad flushes the pool upon every retry before it starts reloading the schema. This is too early as schema reloading might take some time during which new connections might be acquired. The consequence is that:
* upon successful schema cache reload we might have some connections created with the old schema cache
* we close connections upon each retry and under load we will keep closing and re-opening connections until schema cache load succeeds
This change is to make sure we flush the pool only after successful schema cache querying but before loading (so that connections acquired during loading wait for it and do not interfere with timing the loading process).
The current version is too old and it prevented using latest features
like common stanzas and visibility fields.
Signed-off-by: Taimoor Zaeem <taimoorzaeem@gmail.com>
This change introduces a match_log function, that implements lenient matching of log output lines. Tests of log output are retrofited to use the function.
DISCLAIMER:
This commit was authored entirely by a human without the assistance of LLMs.
Using debouncer to trigger schema cache loading makes it difficult to understand when exactly it is triggered.
Fixed integer type mapping in OpenAPI 2.0: replaced the invalid integer format with int32/int64 and added the toSwaggerFormat function to map PostgreSQL types to valid OpenAPI 2.0 formats:
smallint -> int32
integer -> int32
bigint -> int64
To avoid repeated querying of `pg_timezone_names` every time schema
cache is reset, `Prefer: timezone` can be disabled by setting
`db-timezone-enabled = false`.
Signed-off-by: Taimoor Zaeem <taimoorzaeem@gmail.com>
Some helpers are provided for introspecting metrics already (used in JWT cache tests). This change provides facilities to additionally validate emited Observation events.
A new Spec module is also implemented, adding basic tests of schema cache reloading - their main goal is to excercise the new infrastructure.
These files were added to cover the config dumping of
string comparison operators in `JSPath`. Renaming and
adding a comment in these to make it clear.
Signed-off-by: Taimoor Zaeem <taimoorzaeem@gmail.com>
