Re: Fix pgstat_database.c to honor passed database OIDs

On Fri, Apr 10, 2026 at 09:01:32PM +0800, Dapeng Wang wrote:
> Without the patch, calling
> pg_stat_reset_single_table_counters('pg_shdescription'::regclass)
> incorrectly updates the current database's stats_reset timestamp
> while leaving the shared db entry (datid=0) unchanged.
> 
> With the patch, the shared db entry's stats_reset is correctly
> updated, and the current database's timestamp is not affected.

The coalesce() trick to bypass the fact that the reset timestamp may
not be reset was a bit ugly, so I have used instead a second reset.
I have limited the test to check for datid=0, not MyDatabaseId.

There is a bit down in stats.sql an extra portion of the test where we
use twice pg_stats_reset().  One reset could be removed, but I have
left it as-is in case someone decides to shuffle or split things in
this test script, to avoid problems in the future.

And fixed that down to v15.
--
Michael