Feedback-ID: id4a34324:Fastmail
Date: Mon, 30 May 2022 12:10:04 -0700
From: Andres Freund <andres@anarazel.de>
To: Michael Paquier <michael@paquier.xyz>
Cc: Andrey Borodin <x4mmm@yandex-team.ru>,
	Alvaro Herrera <alvherre@alvh.no-ip.org>,
	Robert Haas <robertmhaas@gmail.com>, Peter Geoghegan <pg@bowt.ie>,
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	PostgreSQL mailing lists <pgsql-bugs@lists.postgresql.org>
Subject: Re: BUG #17485: Records missing from Primary Key index when doing
 REINDEX INDEX CONCURRENTLY
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On 2022-05-30 15:54:08 +0900, Michael Paquier wrote:
> Yeah, I agree that we'd better revert c98763bf for the time being.
> And f9900df on top of that?

Well, f9900df needs to be reverted, because it caused the problem at hand, and
is ontop of c98763bf...


> I was trying to think of ways to get an isolation test out of that,
> but that proves to be sort of tricky as we need to manipulate the HOT
> chains after the validation phase has begun with the snapshot from the
> build phase.  It is easy to block before the validation transaction
> starts, like in WaitForLockersMultiple() beforehand, though.

I think it's ok if we have a heuristic test for this kind of thing. It
sometimes can even be good, because it means we'll get different schedulings
over time, hitting "unknown" bugs.

Greetings,

Andres Freund