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

From Justin Pryzby
Subject Re: shared-memory based stats collector - v70
Date
Msg-id 20220406193419.GA24419@telsasoft.com
Whole thread Raw
In response to Re: shared-memory based stats collector - v70  (Andres Freund <andres@anarazel.de>)
List pgsql-hackers
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.




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