MIME-Version: 1.0
References: 
 <CAA5RZ0v0OPGyDpwxkX81CtTt9xsj9-TNxhm=8JdOvEKPsVVFNg@mail.gmail.com>
 <CAA5RZ0vwTY=cVUWSiCFQbz9m5-DQoM=ELLz+ggn+SR-R9H7xpQ@mail.gmail.com>
 <CAHGQGwGA5d0uigSj78xCyjPdc+j3V-qvxk=_NfbV6ScOrGQvbQ@mail.gmail.com>
 <CAA5RZ0sFvN+WJUTxwL0rZQPHcyyCrxsVu+EypxAzRK0Zta71_g@mail.gmail.com>
 <CAHGQGwEP23LzvkuzQPDO55Ys3gqYzY89sK7znAq6kOuUPmrH9A@mail.gmail.com>
In-Reply-To: 
 <CAHGQGwEP23LzvkuzQPDO55Ys3gqYzY89sK7znAq6kOuUPmrH9A@mail.gmail.com>
From: Fujii Masao <masao.fujii@gmail.com>
Date: Mon, 16 Mar 2026 19:01:47 +0900
Message-ID: 
 <CAHGQGwFcay_tX=7HSS=N=+Yd0FLEm2GrJgwxnqHM4wvxX0B=4g@mail.gmail.com>
Subject: Re: Add missing stats_reset column to pg_statio_all_sequences view
To: Sami Imseih <samimseih@gmail.com>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>,
 shihao zhong <zhong950419@gmail.com>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Archived-At: 
 <https://www.postgresql.org/message-id/CAHGQGwFcay_tX%3D7HSS%3DN%3D%2BYd0FLEm2GrJgwxnqHM4wvxX0B%3D4g%40mail.gmail.com>
Precedence: bulk

On Mon, Mar 16, 2026 at 5:27=E2=80=AFPM Fujii Masao <masao.fujii@gmail.com>=
 wrote:
>
> On Fri, Mar 13, 2026 at 11:52=E2=80=AFAM Sami Imseih <samimseih@gmail.com=
> wrote:
> >
> > > it would be better to verify that the stats of the specified sequence=
 are
> > > actually reset by using pg_stat_reset_single_table_counters().
> > >
> > > Also, the documentation for pg_stat_reset_single_table_counters() sho=
uld
> > > mention that it can reset sequence statistics as well.
> >
> > good points.
> >
> > For the  documentation of pg_stat_reset_single_table_counters(), I also
> > mentioned materialized views for completeness.
>
> Thanks for updating the patch!
>
> I made a few cosmetic changes and pushed the patch. Thanks!

Hmm... buildfarm member crake reported a pg_upgradeCheck failure, and it se=
ems
the test I added last time is causing it :(

--- /home/andrew/bf/root/HEAD/pgsql/src/test/regress/expected/stats.out
2026-03-16 04:27:05.805748763 -0400
+++ /home/andrew/bf/root/HEAD/pgsql.build/testrun/pg_upgrade/002_pg_upgrade=
/data/results/stats.out
2026-03-16 05:17:15.460202339 -0400
@@ -1196,7 +1196,7 @@
   FROM pg_statio_all_sequences WHERE relname =3D'test_seq1';
  ?column? | ?column?
 ----------+----------
- t        |        0
+ t        |        1
 (1 row)

The test assumed that blks_read and blks_hit in pg_statio_all_sequences wou=
ld
be zero immediately after calling pg_stat_reset_single_table_counters().
However, on crake, either of them became 1 even right after the reset.
This might happen if another process (e.g., autovacuum) accesses
the sequence in the short window between the reset and the query of
pg_statio_all_sequences??? More investigation would be necessary.

Since checking the blks_read and blks_hit counters in pg_statio_all_sequenc=
es
can make the test unstable, I'm thinking of removing that part of the test.

Regards,

--=20
Fujii Masao