Re: race condition in pg_class

Noah Misch <noah(at)leadboat(dot)com> writes:
> On Thu, Sep 11, 2025 at 12:36:04PM -0400, Tom Lane wrote:
>> It emerges that the "ALTER DATABASE regression_utf8 RESET TABLESPACE"
>> command is a complete no-op [1]. I am guessing that that was not the
>> behavior you had in mind, and am wondering if we are losing any test
>> coverage thereby. Did you have a specific reason for manipulating the
>> TABLESPACE property and not some random GUC setting?

> I have no specific notes or memories about that RESET TABLESPACE, but I likely
> wanted "SET TABLESPACE pg_default". RESET TABLESPACE may still have the
> effect of loading a catcache entry, as a later comment says:
> ...
> I'm inclined to change it as
> attached. This doesn't reduce database.sql test coverage of dbcommands.c or
> catcache.c, so I'll bet it doesn't lose anything vs. the original database.sql
> commit. Some check-tests runs showed it adding database.sql coverage of
> catcache.c:1908-1911 and catcache.c:1983-1984, so that's a bonus.

Thanks, that looks sane.

> Do you plan to back-patch that? That should dictate whether I back-patch the
> test change.

That change will convert some commands that are currently no-ops into
errors, which doesn't seem like a great thing to do in minor releases.
However ... it might still be okay to cram it into v18. Do you have
an opinion about that?

regards, tom lane