Re: Add mode column to pg_stat_progress_vacuum

On Wed, Oct 8, 2025 at 4:34 AM Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
>
> On Tue, Oct 7, 2025 at 12:01 PM Nathan Bossart <nathandbossart(at)gmail(dot)com> wrote:
> >
> > On Tue, Oct 07, 2025 at 10:17:38AM -0700, Masahiko Sawada wrote:
> > > Right. I think we cannot display both things in one mode column. Since
> > > both manual vacuums and anti-wraparound autovacuums can enter the
> > > failsafe mode dynamically, if we show "failsafe" in the mode column,
> > > we would lose the information "why is this vacuum running". I guess we
> > > would need separate columns. For example, I guess that the column
> > > showing "how is it operating under the hood" can have three values:
> > > "normal", "aggressive" (disables VM optimization), and "failsafe"
> > > (implies aggressive vacuum and disables many things to prioritize XID
> > > freezing).
> >
> > Am I understanding correctly that your idea is to have a "reason" column
> > that would have values like "manual", "normal autovacuum", and "autovacuum
> > for wraparound", and a "mode" column that would have values like "normal",
> > "agressive", and "failsafe"?
>
> Right. The first column provides an insight into whether or not the
> running vacuum is cancellable, and the second column provides
> information on how vacuums are actually processing tables under the
> hood. Users are able to get the former information by checking
> pg_stat_activity too but the latter information is available only in
> server logs.

Thanks for the clarification. I agree with your proposal. Separating
the "reason" from the "mode" into two columns is a great idea that
will provide much clearer insight for DBAs.

--
Best regards,
Shinya Kato
NTT OSS Center