Re: shared-memory based stats collector - v70

Hi,

On 2022-04-06 12:14:35 -0700, Lukas Fittl wrote:
> On Tue, Apr 5, 2022 at 8:00 PM Andres Freund <andres(at)anarazel(dot)de> wrote:
>
> > Here comes v70:
> >
>
> Some small nitpicks on the docs:

Thanks!

> > From 13090823fc4c7fb94512110fb4d1b3e86fb312db Mon Sep 17 00:00:00 2001
> > From: Andres Freund <andres(at)anarazel(dot)de>
> > Date: Sat, 2 Apr 2022 19:38:01 -0700
> > Subject: [PATCH v70 14/27] pgstat: update docs.
> > ...
> > diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
> > - These parameters control server-wide statistics collection
> features.
> > - When statistics collection is enabled, the data that is produced
> can be
> > + These parameters control server-wide cumulative statistics system.
> > + When enabled, the data that is collected can be
>
> Missing "the" ("These parameters control the server-wide cumulative
> statistics system").

> > diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
> > + any of the accumulated statistics, acessed values are cached until
> the end
>
> "acessed" => "accessed"

> > + <varname>stats_fetch_consistency</varname> can be set
> > + <literal>snapshot</literal>, at the price of increased memory usage
> for
>
> Missing "to" ("can be set to <literal>snapshot</literal>")

Fixed.

> > + caching not-needed statistics data. Conversely, if it's known that
> statistics
>
> Double space between "data." and "Conversely" (not sure if that matters)
> > + current transaction's statistics snapshot or cached values (if any).
> The
>
> Double space between "(if any)." and "The" (not sure if that matters)

That's done pretty widely in the docs and comments.

> > + 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?

Greetings,

Andres Freund