Re: another autovacuum scheduling thread

HI Nathan Bossart

> + if (vactuples > vacthresh)
> + {
> + *dovacuum = true;
> + *score = Max(*score, (double) vactuples / Max(vacthresh, 1));
> + }
> +
> + if (vac_ins_base_thresh >= 0 && instuples > vacinsthresh)
> + {
> + *dovacuum = true;
> + *score = *score = Max(*score, (double) instuples / Max(vacinsthresh,
1));
> + }
I think it ( *score = *score = Max(*score, (double) instuples /
Max(vacinsthresh, 1));) I believe this must be a slip of the hand on your
part, having copied an extra one.
I also suggest add debug log for score
ereport(DEBUG2,
(errmsg("autovacuum candidate: %s (score=%.3f)",
get_rel_name(table->oid), table->score)));

> + effective_xid_failsafe_age = Max(vacuum_failsafe_age,
> + autovacuum_freeze_max_age * 1.05);
Typically, DBAs avoid setting autovacuum_freeze_max_age too close to
vacuum_failsafe_age. Therefore, your logic most likely uses the
vacuum_failsafe_age value.
Would taking the average of the two be a better approach?
#
root(at)localhost:/data/pgsql/pg18data# grep vacuum_failsafe_age
postgresql.conf
#vacuum_failsafe_age = 1600000000
root(at)localhost:/data/pgsql/pg18data# grep autovacuum_freeze_max_age
postgresql.conf
#autovacuum_freeze_max_age = 200000000 # maximum XID age before forced
vacuum

Thanks

On Wed, Oct 29, 2025 at 6:45 AM Sami Imseih <samimseih(at)gmail(dot)com> wrote:

> > Done.
>
> My compiler is complaining about v6
>
> "../src/backend/postmaster/autovacuum.c:3293:32: warning: operation on
> ‘*score’ may be undefined [-Wsequence-point]
> 3293 | *score = *score = Max(*score, (double)
> instuples / Max(vacinsthresh, 1));
> [2/2] Linking target src/backend/postgres"
>
> shouldn't just be like below?
>
> *score =Max(*score, (double) instuples / Max(vacinsthresh, 1));
>
>
> --
> Sami
>
>
>