Re: another autovacuum scheduling thread - Mailing list pgsql-hackers

On Sat, 25 Oct 2025 at 04:08, Nathan Bossart <nathandbossart@gmail.com> wrote:
> Here is an updated patch based on the latest discussion.

Thanks. I've just had a look at it. A few comments and questions.

1) The subtraction here looks back to front:

+ xid_age = TransactionIdIsNormal(relfrozenxid) ? relfrozenxid - recentXid : 0;
+ mxid_age = MultiXactIdIsValid(relminmxid) ? relminmxid - recentMulti : 0;

2) Would it be better to move all the code that sets the xid_score and
mxid_score to under an "if (force_vacuum)"? Those two variables could
be declared in there too.

3) Could the following be refactored a bit so we only check the "relid
!= StatisticRelationId" condition once?

+ if (relid != StatisticRelationId &&
+ classForm->relkind != RELKIND_TOASTVALUE)

Something like:

/* ANALYZE refuses to work with pg_statistic and we don't analyze
toast tables */
if (anltuples > anlthresh && relid != StatisticRelationId &&
    classForm->relkind != RELKIND_TOASTVALUE)
{
    *doanalyze = true;
    // calc analyze score and Max with *score
}
else
  *doanalyze = false;

then delete:

/* ANALYZE refuses to work with pg_statistic */
if (relid == StatisticRelationId)
    *doanalyze = false;

4) Should these be TransactionIds?

+ uint32 xid_age;
+ uint32 mxid_age;

5) Instead of:

+ double score = 0.0;

Is it better to zero the score inside relation_needs_vacanalyze() so
it works the same as the other output parameters?

David