MIME-Version: 1.0
References: <20260324151133.7940a5c1f2ebd594d54da481@sraoss.co.jp>
 <CAA5RZ0snnePNW1NKGKh+NyJ1CY26T5F_6-tTq+BHWM2kj1fN1g@mail.gmail.com>
 <20260325012847.e026ba1860c07288efe3e97d@sraoss.co.jp>
 <acNDTM20nJjDYZxq@paquier.xyz>
 <20260325132451.807ebb159f3b11e88ad4ecc0@sraoss.co.jp>
In-Reply-To: <20260325132451.807ebb159f3b11e88ad4ecc0@sraoss.co.jp>
From: Sami Imseih <samimseih@gmail.com>
Date: Wed, 25 Mar 2026 12:12:35 -0500
Message-ID: 
 <CAA5RZ0v=tdz3nGgq-Sk7hEwac1P=5J7d+SXd+62azfqiogdG6w@mail.gmail.com>
Subject: Re: Track skipped tables during autovacuum and autoanalyze
To: Yugo Nagata <nagata@sraoss.co.jp>
Cc: Michael Paquier <michael@paquier.xyz>,
 Pgsql Hackers <pgsql-hackers@postgresql.org>
Content-Type: text/plain; charset="UTF-8"
Archived-At: 
 <https://www.postgresql.org/message-id/CAA5RZ0v%3Dtdz3nGgq-Sk7hEwac1P%3D5J7d%2BSXd%2B62azfqiogdG6w%40mail.gmail.com>
Precedence: bulk

> > On Wed, Mar 25, 2026 at 01:28:47AM +0900, Yugo Nagata wrote:
> > > Although the timestamps are overwritten on each skipped autovacuum or
> > > autoanalyze, they still indicate when the last attempt was made. This
> > > can help users confirm that autovacuum is actively attempting to run,
> > > and that the issue is due to repeated skips rather than inactivity.
> > >
> > > While counters can indicate overall activity, they do not reveal when
> > > the last skip occurred. With timestamps, users can immediately see the
> > > most recent attempt, even without a separate dashboard or historical
> > > tracking.
> > >
> > > Therefore, counters are useful for monitoring overall activity, but
> > > timestamps give additional, complementary information, so it seems
> > > worthwhile to include them too.
> >
> > Hmm..  I can buy this argument for the timestamps, especially for
> > database with many relations of various sizes that could take a
> > various amount of time to process.  The timestamps could offer hints
> > about the time it takes between the skips, even if snapshots of the
> > stats data are not taken at a very aggressive frequency.

I'm fine with adding timestamps, as there seem to be convincing
reasons to add them.
My other concern is bloat of the pg_stat_all_tables view. This patch
adds 4 columns, or
8 if we also include manual vacuum and analyze (which I think we should).

Given that, should we also start thinking about splitting the vacuum
activity related
columns into a dedicated view and out of pg_stat_all_tables for v20?

--
Sami Imseih
Amazon Web Services (AWS)