From: Tom Lane <tgl@sss.pgh.pa.us>
To: "David G. Johnston" <david.g.johnston@gmail.com>
cc: Rui An <rueian.huang@gmail.com>,
        "pgsql-bugs@postgresql.org" <pgsql-bugs@postgresql.org>
Subject: Re: Many queries stuck for waiting MultiXactOffsetControlLock on
 PostgreSQL 9.6.1 replica
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Comments: In-reply-to "David G. Johnston" <david.g.johnston@gmail.com>
	message dated "Sun, 01 Aug 2021 22:48:40 -0700"
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Date: Mon, 02 Aug 2021 10:18:46 -0400
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"David G. Johnston" <david.g.johnston@gmail.com> writes:
> And you should also be prepared for the possibility that 9.6 is
> discontinued before there is a fix in which case you=E2=80=99d have to u=
pgrade to
> v10 (at least) to get said fix.

If the fix is as complex as what's being discussed over at [1], there
is zero chance that it'd be back-patched at all.

Nonetheless, still being on 9.6.1 at this late date is next door to
software malpractice.  There are a *lot* of known bugs in that version
that have been fixed, including performance issues [2].

			regards, tom lane

[1] https://www.postgresql.org/message-id/flat/2BEC2B3F-9B61-4C1D-9FB5-5FA=
B0F05EF86%40yandex-team.ru
[2] https://www.postgresql.org/docs/release/