Re: Re: [COMMITTERS] pgsql: Use LEFT JOINs in some system views in case referenced row doesn

* Tom Lane (tgl(at)sss(dot)pgh(dot)pa(dot)us) wrote:
> Michael Paquier <michael(dot)paquier(at)gmail(dot)com> writes:
> > On Sun, Sep 11, 2016 at 5:21 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> >> The fact that the pg_stat_replication view does show walsender processes
> >> seems like possibly a reasonable argument for not showing them in
> >> pg_stat_activity. But we'd have to do some rejiggering of the view
> >> definition to make that happen.
>
> > We may actually had better show WAL sender processes in
> > pg_stat_activity. An argument in favor of that is the tracking of
> > WaitEventSet events (or latches if you want).
>
> Also, walsenders count against MaxBackends don't they? So not showing
> them could contribute to confusion about why an installation is hitting
> the connection limit.
>
> If we do keep them in the view, I would definitely vote for having them
> set their "query" fields to something that shows they're walsenders.
> It's awfully late to be doing anything complicated there for 9.6,
> but we could just set the query to "walsender" and plan to improve
> on that in future releases.

+1

Thanks!

Stephen