Horton

Re: shared-memory based stats collector - v70

Lukas Fittl <lukas@fittl.com>

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From: Lukas Fittl <lukas@fittl.com>
To: Justin Pryzby <pryzby@telsasoft.com>
Cc: Andres Freund <andres@anarazel.de>, "David G. Johnston" <david.g.johnston@gmail.com>, Kyotaro Horiguchi <horikyota.ntt@gmail.com>, Thomas Munro <thomas.munro@gmail.com>, melanieplageman@gmail.com, pgsql-hackers@lists.postgresql.org
Date: 2022-04-06T19:37:20Z
Lists: 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