Horton

Re: compute_query_id and pg_stat_statements

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

View thread View on postgr.es
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Julien Rouhaud <rjuju123@gmail.com>
Cc: Bruce Momjian <bruce@momjian.us>, Stephen Frost <sfrost@snowman.net>, Christoph Berg <myon@debian.org>, Pavel Stehule <pavel.stehule@gmail.com>, Kyotaro Horiguchi <horikyota.ntt@gmail.com>, Magnus Hagander <magnus@hagander.net>, Fujii Masao <masao.fujii@oss.nttdata.com>, Michael Paquier <michael@paquier.xyz>, Andres Freund <andres@anarazel.de>, Alvaro Herrera <alvherre@alvh.no-ip.org>, Peter Eisentraut <peter.eisentraut@enterprisedb.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2021-05-14T01:47:02Z
Lists: pgsql-hackers 
Julien Rouhaud <rjuju123@gmail.com> writes:
> On Fri, May 14, 2021 at 3:12 AM Bruce Momjian <bruce@momjian.us> wrote:
>> I was surprised it was ~2%.

> Just to be clear, the 2% was a worst case scenario, ie. a very fast
> read-only query on small data returning a single row.  As soon as you
> get something more realistic / expensive the overhead goes away.

Of course, for plenty of people that IS the realistic scenario that
they care about max performance for.

			regards, tom lane

Commits

  1. Allow compute_query_id to be set to 'auto' and make it default

  2. Move pg_stat_statements query jumbling to core.