Re: Intermittent buildfarm failures on wrasse

On Wed, Apr 13, 2022 at 4:38 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> So what seems to be happening on wrasse is that a background
> autovacuum (or really autoanalyze?) is preventing pages from
> being marked all-visible not only during test_setup.sql but
> also create_index.sql; but it's gone by the time sanity_check.sql
> runs.

I agree that it would need to be an autoanalyze (due to the
PROC_IN_VACUUM optimization).

> It seems like a reliable fix might require test_setup to wait
> for any background autovac to exit before it does its own
> vacuums.  Ick.

This is hardly a new problem, really. I wonder if it's worth inventing
a comprehensive solution. Some kind of infrastructure that makes
VACUUM establish a next XID up-front (by calling
ReadNextTransactionId()), and then find a way to run with an
OldestXmin that's >= the earleir "next" XID value. If necessary by
waiting.

-- 
Peter Geoghegan