Re: Replication slot stats misgivings

Hi,

On 2021-03-20 10:28:06 +0530, Amit Kapila wrote:
> On Sat, Mar 20, 2021 at 9:25 AM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
> > This idea is worth exploring to address the complaints but what do we
> > do when we detect that the stats are from the different slot? It has
> > mixed of stats from the old and new slot. We need to probably reset it
> > after we detect that.
> >
>
> What if the user created a slot with the same name after dropping the
> slot and it has used the same index. I think chances are less but
> still a possibility, but maybe that is okay.
>
> > What if after some frequency (say whenever we
> > run out of indexes) we check whether the slots we are maintaining is
> > pgstat.c have some stale slot entry (entry exists but the actual slot
> > is dropped)?
> >
>
> A similar drawback (the user created a slot with the same name after
> dropping it) exists with this as well.

pgstat_report_replslot_drop() already prevents that, no?

Greetings,

Andres Freund