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

From David Rowley
Subject Re: another autovacuum scheduling thread
Date
Msg-id CAApHDvohuOypudeuj7nVb9XCyg=u2JR2j00j4zYPGzBjn78piA@mail.gmail.com
Whole thread Raw
In response to Re: another autovacuum scheduling thread  (wenhui qiu <qiuwenhuifx@gmail.com>)
List pgsql-hackers
On Thu, 30 Oct 2025 at 19:48, wenhui qiu <qiuwenhuifx@gmail.com> wrote:
>      I think there might be some misunderstanding — I’m only suggesting changing
> effective_xid_failsafe_age = Max(vacuum_failsafe_age,
>                                  autovacuum_freeze_max_age * 1.05);
> to
> effective_xid_failsafe_age = (vacuum_failsafe_age + autovacuum_freeze_max_age) / 2.0;
> In the current logic, effective_xid_failsafe_age is almost always equal to vacuum_failsafe_age.
> As a result, increasing the vacuum priority only when a table’s age reaches vacuum_failsafe_age is too late.

I understand your proposal. The autovacuum will trigger for the
wraparound at autovacuum_freeze_max_age, so for autovacuum still not
to have gotten to the table by the time the table is aged at
vacuum_failsafe_age, it means autovacuum isn't working quickly enough
to get through the workload, therefore the problem is with the speed
of autovacuum not the priority of autovacuum.

David



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