Re: Fix race condition in pg_get_publication_tables with concurrent DROP TABLE

Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>

From: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>

To: shveta malik <shveta.malik@gmail.com>

Cc: Ajin Cherian <itsajin@gmail.com>, Bertrand Drouvot <bertranddrouvot.pg@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>

Date: 2026-05-04T02:34:00Z

Lists: pgsql-hackers

Attachments

v6-0001-Fix-pg_get_publication_tables-race-with-concurren.patch (application/x-patch) patch v6-0001
v6-0001-PG18-Fix-pg_get_publication_tables-race-with-conc.patch (application/x-patch) patch v6-0001
v6-0001-PG17-Fix-pg_get_publication_tables-race-with-conc.patch (application/x-patch) patch v6-0001
v6-0001-PG16-Fix-pg_get_publication_tables-race-with-conc.patch (application/x-patch) patch v6-0001

Hi,

On Wed, Apr 29, 2026 at 12:15 AM Bharath Rupireddy
<bharath.rupireddyforpostgres@gmail.com> wrote:
>
> Fixed. Please find the attached v5 patch.
>
> The fix is needed only for PG16 and later, not PG15 or PG14. The bug
> was introduced by b7ae03953690 [1] in PG16, which added a table_open()
> call in pg_get_publication_tables(). PG15 and earlier only use
> get_rel_namespace() and syscache lookups, both of which gracefully
> handle dropped relations (returning InvalidOid/false rather than
> erroring).
>
> I verified the bug and the fix on all affected branches. Please find
> the attached version-specific patches for backpatching. Thank you!
>
> [1] b7ae03953690 - Ignore dropped and generated columns from the column list

Please find the attached v6 patch, which fixes a test failure on
FreeBSD. This variant of the build forces parallel query via
debug_parallel_query=regress, causing the pg_get_publication_tables
injection point to fire in parallel workers as well. I disabled forced
parallel query for this test case.

Thank you!


--
Bharath Rupireddy
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