Re: Design of pg_stat_subscription_workers vs pgstats

On Sat, Feb 19, 2022 at 5:32 AM Andres Freund <andres@anarazel.de> wrote:
>
> Hi,
>
> On 2022-02-18 17:26:04 +0900, Masahiko Sawada wrote:
> > With this change, pg_stat_subscription_workers will be like:
> >
> > * subid
> > * subname
> > * subrelid
> > * error_count
> > * last_error_timestamp
>
> > This view will be extended by adding transaction statistics proposed
> > on another thread[1].
>
> I do not agree with these bits. What's the point of these per-relation stats
> at this poitns.  You're just duplicating the normal relation pg_stats here.
>
> I really think we just should drop pg_stat_subscription_workers. Even if we
> don't, we definitely should rename it, because it still isn't meaningfully
> about workers.

The view has stats per subscription worker (i.e., apply worker and
tablesync worker), not per relation. The subrelid is OID of the
relation that the tablesync worker is synchronizing. For the stats of
apply workers, it is null.

Regards,

--
Masahiko Sawada
EDB:  https://www.enterprisedb.com/