Re: pgsql: Fix search_path to a safe value during maintenance operations.

On Fri, 2023-06-09 at 15:16 -0700, Jeff Davis wrote:
> On Fri, 2023-06-09 at 20:54 +0000, Jeff Davis wrote:
> > Fix search_path to a safe value during maintenance operations.
>
> Looks like this is causing pg_amcheck failures in the buildfarm.
> Investigating...

It looks related to bt_index_check_internal(), which is called by SQL
functions bt_index_check() and bt_index_parent_check(). SQL functions
can be called in parallel, so it raises the error:

ERROR: cannot set parameters during a parallel operation

because commit 05e1737351 added the SetConfigOption() line. Normally
those functions would not be called in parallel, but
debug_parallel_mode makes that happen.

Attached a patch to mark those functions as PARALLEL UNSAFE, which
fixes the problem.

Alternatively, I could just take out that line, as those SQL functions
are not controlled by the MAINTAIN privilege. But for consistency I
think it's a good idea to leave it in so that index functions are
called with the right search path for amcheck.

--
Jeff Davis
PostgreSQL Contributor Team - AWS