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Date: Thu, 21 Mar 2019 18:06:06 -0300
From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: Alexander Korotkov <aekorotkov@gmail.com>
Cc: Simon Riggs <simon@2ndquadrant.com>, Andres Freund <andres@anarazel.de>,
	Andrey Borodin <x4mmm@yandex-team.ru>, Peter Geoghegan <pg@bowt.ie>,
	chenhj <chjischj@163.com>, Teodor Sigaev <teodor@sigaev.ru>,
	PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: Connections hang indefinitely while taking a gin index's LWLock
 buffer_content lock
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Precedence: bulk

On 2019-Mar-21, Alexander Korotkov wrote:

> However, I think this still can be backpatched correctly.  We can
> determine whether xlog record data contains deleteXid by its size.
> See the attached patch.  I haven't test this yet.  I'm going to test
> it.  If OK, then push.

Wow, this is so magical that I think it merits a long comment explaining
what is going on.

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services