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

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",

Based on the last reports, we have no failures:
https://buildfarm.postgresql.org/cgi-bin/show_history.pl?nm=batta&br=master

If this was not caught, we have either:
- A problem in 027 itself, with coverage in the regression tests but
fail to detect the failure in the test. I recall that we are careful
about checking the standby state in 027 as an inconsistency would be
the same as a FATAL in a standby.
- Lack of coverage in the main regression test suite.

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.
--
Michael