Re: shared-memory based stats collector - v70 - Mailing list pgsql-hackers

From Lukas Fittl
Subject Re: shared-memory based stats collector - v70
Date
Msg-id CAP53PkynGdV-xff8p2mdQ3WAw+N6darMZpKzu=mj1cNvrQmWXQ@mail.gmail.com
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In response to Re: shared-memory based stats collector - v66  (Andres Freund <andres@anarazel.de>)
List pgsql-hackers
On Wed, Apr 6, 2022 at 12:34 PM Justin Pryzby <pryzby@telsasoft.com> wrote:
On Wed, Apr 06, 2022 at 12:27:34PM -0700, Andres Freund wrote:
> > > +   next use of statistical information will cause a new snapshot to be built
> > > +   or accessed statistics to be cached.
> >
> > I believe this should be an "and", not an "or". (next access builds both a
> > new snapshot and caches accessed statistics)
>
> I *think* or is correct? The new snapshot is when stats_fetch_consistency =
> snapshot, the cached is when stats_fetch_consistency = cache. Not sure how to
> make that clearer without making it a lot longer. Suggestions?

I think it's correct.  Maybe it's clearer to say:

+   next use of statistical information will (when in snapshot mode) cause a new snapshot to be built
+   or (when in cache mode) accessed statistics to be cached.

Ah, yes, that does clarify what was meant.

+1 to Justin's edit, or something like it.

Thanks,
Lukas

--
Lukas Fittl

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