Date: Wed, 8 Oct 2025 17:27:27 -0700
From: Jeremy Schneider <schneider@ardentperf.com>
To: David Rowley <dgrowleyml@gmail.com>
Cc: Sami Imseih <samimseih@gmail.com>, Nathan Bossart
 <nathandbossart@gmail.com>, pgsql-hackers@postgresql.org
Subject: Re: another autovacuum scheduling thread
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On Thu, 9 Oct 2025 12:59:23 +1300
David Rowley <dgrowleyml@gmail.com> wrote:

> I believe that is methodology for processing work applies much better
> in scenarios where there's no new work continually arriving and
> there's no adverse effects from giving a lower priority to certain
> portions of the work. I don't think you can apply that so easily to
> autovacuum as there are scenarios where the work can pile up faster
> than it can be handled.  Also, smaller tables can bloat in terms of
> growth proportional to the original table size much more quickly than
> larger tables and that could have huge consequences for queries to
> small tables which are not indexed sufficiently to handle being
> becoming bloated and large.

I'm arguing that it works well with autovacuum. Not saying there aren't
going to be certain workloads that it's suboptimal for. We're talking
about sorting by (M)XID age. As the clock continues to move forward any
table that doesn't get processed naturally moves up the queue for the
next autovac run. I think the concerns are minimal here and this would
be a good change in general.

-Jeremy


-- 
To know the thoughts and deeds that have marked man's progress is to
feel the great heart throbs of humanity through the centuries; and if
one does not feel in these pulsations a heavenward striving, one must
indeed be deaf to the harmonies of life.

Helen Keller, The Story Of My Life, 1902, 1903, 1905, introduction by
Ralph Barton Perry (Garden City, NY: Doubleday & Company, 1954), p90.