From: Tom Lane <tgl@sss.pgh.pa.us>
To: Mike Schanne <mschanne@kns.com>
cc: "'pgsql-performance@postgresql.org'" <pgsql-performance@postgresql.org>
Subject: Re: autovacuum locking question
In-reply-to: <1f62dd52283e4aa3b5d730d546cc4c02@USEPRDEX1.corp.kns.com>
References: <0871fcf35ceb4caa8a2204ca9c38e330@USEPRDEX1.corp.kns.com>
 <26221.1575589746@sss.pgh.pa.us>
 <1f62dd52283e4aa3b5d730d546cc4c02@USEPRDEX1.corp.kns.com>
Comments: In-reply-to Mike Schanne <mschanne@kns.com>
	message dated "Fri, 06 Dec 2019 15:46:15 +0000"
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-ID: <16066.1575652339.1@sss.pgh.pa.us>
Content-Transfer-Encoding: quoted-printable
Date: Fri, 06 Dec 2019 12:12:19 -0500
Message-ID: <16067.1575652339@sss.pgh.pa.us>
Precedence: bulk

Mike Schanne <mschanne@kns.com> writes:
> Is this what you are referring to?
> - Prevent VACUUM from trying to freeze an old multixact ID involving a s=
till-running transaction (Nathan Bossart, Jeremy Schneider)
> This case would lead to VACUUM failing until the old transaction termina=
tes.
> https://www.postgresql.org/docs/release/9.6.16/

Hmmm ... after digging through the commit log, it seems the improvements
I was thinking of were all pre-9.6.  The only post-9.6 vacuum truncation
performance fix I can find is

https://git.postgresql.org/gitweb/?p=3Dpostgresql.git&a=3Dcommitdiff&h=3D7=
e26e02ee

which came in in v10.

			regards, tom lane