Re: Resetting spilled txn statistics in pg_stat_replication

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.

Anyway I think the most significant point of implementing the feature
would be user interface.  Adding pg_stat_replication_reset(pid int)
doesn't seem to be a good thing to do..

regards.

-- 
Kyotaro Horiguchi
NTT Open Source Software Center