Re: gistkillitems can LP_DEAD-mark the wrong tuples on a rescan

On Sat, Aug 15, 2026 at 7:38 PM Michael Paquier <michael(at)paquier(dot)xyz> wrote:
> On Sat, Aug 15, 2026 at 06:06:25PM -0400, Peter Geoghegan wrote:
> > This is *probably* only a bug on master, since only master has commit
> > 9c9ddf109, which taught gistkillitems to run against a single-page
> > GiST index. However, we don't correctly reset the state on a rescan in
> > any version, which seems dicey even without commit 9c9ddf109.
>
> My buildfarm member batta is running recovery test 027 with
> wal_consistency_checking, with:
> PG_TEST_EXTRA => "regress_dump_restore wal_consistency_checking saslprep",

Did you intend to respond to the nearby thread about
wal_consistency_checking? This thread is about LP_DEAD marking going
wrong in gist, but technically it's unrelated to the
wal_consistency_checking thing.

> So, which one is it? Perhaps number 2), because such a test would be
> expensive to run in the main regression test suite? It sounds to me
> that we need a bit more than just your patch here.

We do have test coverage that might have caught the F_TUPLES_DELETED
issue that I complained about on the other thread, but it's not part
of the main regression tests. It's in
src/test/modules/index/specs/killtuples.spec. Could that be why?

--
Peter Geoghegan