Re: Resetting spilled txn statistics in pg_stat_replication

On Tue, 2 Jun 2020 at 16:00, Kyotaro Horiguchi <horikyota.ntt@gmail.com> wrote:
>
> At Tue, 2 Jun 2020 15:17:36 +0900, Masahiko Sawada <masahiko.sawada@2ndquadrant.com> wrote in
> > Hi all,
> >
> > Tracking of spilled transactions has been introduced to PG13. These
> > new statistics values, spill_txns, spill_count, and spill_bytes, are
> > cumulative total values unlike other statistics values in
> > pg_stat_replication. How can we reset these values? We can reset
> > statistics values in other statistics views using by
> > pg_stat_reset_shared(), pg_stat_reset() and so on. It seems to me that
> > the only option to reset spilled transactions is to restart logical
> > replication but it's surely high cost.
> >
> > It might have been discussed during development but it's worth having
> > a SQL function to reset these statistics?
>
> Actually, I don't see pg_stat_reset() useful so much except for our
> regression test (or might be rather harmful for monitoring aids).  So
> I doubt the usefulness of the feature, but having it makes things more
> consistent.

IMO these reset functions are useful for verifications. I often use
them before starting performance evaluations.

Regards,

-- 
Masahiko Sawada            http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services