Re: REINDEX INDEX results in a crash for an index of pg_class since 9.6

Andres Freund <andres@anarazel.de> writes:
> On 2019-04-30 14:05:50 -0400, Tom Lane wrote:
>> Possibly we could run them in a TAP test that configures a cluster
>> with autovac disabled?

> Hm. Would it be sufficient to instead move them to a non-concurrent
> test group, and stick a BEGIN; LOCK pg_class, ....; COMMIT; around it?

Doubt it.  Maybe you could get away with it given that autovacuum and
autoanalyze only do non-transactional updates to pg_class, but that
seems like a pretty shaky assumption.

> This is a pretty finnicky area of the code, with obviously not enough
> test coverage.  I'm inclined to remove them from the back branches, and
> try to get them working in master?

I think trying to get this "working" is a v13 task now.  We've obviously
never tried to stress the case before, so you're neither fixing a
regression nor fixing a new-in-v12 issue.

            regards, tom lane