Re: monitoring usage count distribution

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Nathan Bossart <nathandbossart@gmail.com>, pgsql-hackers@postgresql.org, schneider@ardentperf.com
Date: 2023-04-04T18:40:02Z
Lists: pgsql-hackers
Robert Haas <robertmhaas@gmail.com> writes:
> On Mon, Jan 30, 2023 at 6:30 PM Nathan Bossart <nathandbossart@gmail.com> wrote:
>> My colleague Jeremy Schneider (CC'd) was recently looking into usage count
>> distributions for various workloads, and he mentioned that it would be nice
>> to have an easy way to do $SUBJECT.

> I'm skeptical that pg_buffercache_summary() is a good idea at all, but
> having it display the average usage count seems like a particularly
> poor idea. That information is almost meaningless. Replacing that with
> a six-element integer array would be a clear improvement and, IMHO,
> better than adding yet another function to the extension.

I had not realized that pg_buffercache_summary() is new in v16,
but since it is, we still have time to rethink its definition.
+1 for de-aggregating --- I agree that the overall average is
unlikely to have much value.

			regards, tom lane



Commits

  1. Add pg_buffercache_usage_counts() to contrib/pg_buffercache.