Re: autovacuum: automatically propagate updated parameters

Hi,

On Mon, Aug 24, 2026 at 3:16 PM Daniel Gustafsson <daniel(at)yesql(dot)se> wrote:
>
> > On 25 Aug 2026, at 00:06, Zsolt Parragi <zsolt(dot)parragi(at)percona(dot)com> wrote:
> >
> >> I understand that having a test for this in the first place could have
> >> helped catch this issue. However, I don't see a strong point in having
> >> one now. Can we test it manually and get the fix alone?
> >
> > I mainly added the testcase as a repro, I am not sure how useful it is
> > as an actual test case. But if we want to keep it, I can certainly
> > reduce it.
>
> I think there is value in having a test, especially if we can roll it into 001
> as quick step.

+1. How about adding the test in the existing
001_parallel_autovacuum.pl instead of a new TAP test file?

> >> How about propagating the params to parallel workers launched by
> >> autovacuum right after updating cost limits in
> >> AutoVacuumUpdateCostLimit()?
> >
> > That could work too, I used the current location because most of the
> > parallel related things, including the other call to
> > parallel_vacuum_propagate_shared_delay_params is in vacuum.c, not in
> > autovacuum.c
>
> There is also strong value in not changing things too drastic at this point in
> the cycle.

Agreed. I'm fine with the v1 approach and backpatching to PG19.

--
Bharath Rupireddy
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