From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: Antonin Houska <ah@cybertec.at>
Cc: Arseny Sher <a.sher@postgrespro.ru>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>
Subject: Re: Fix slot's xmin advancement and subxact's lost snapshots in decoding.
Date: Mon, 18 Jun 2018 14:04:19 -0400
Message-ID: <20180618180419.mysc6nxvntgvfgg2@alvherre.pgsql> (raw)
In-Reply-To: <15387.1528700867@localhost>
On 2018-Jun-11, Antonin Houska wrote:
> Arseny Sher <a.sher@postgrespro.ru> wrote:
> > Please see detailed description of the issues, tests which reproduce
> > them and fixes in the attached patch.
>
> I've played with your tests and gdb for a while, both w/o and with your
> patch. I think I can understand both problems. I could not invent simpler way
> to fix them.
>
> One comment about the coding: since you introduce a new transaction list and
> it's sorted by LSN, I think you should make the function AssertTXNLsnOrder()
> more generic and use it to check the by_base_snapshot_lsn list too. For
> example call it after the list insertion and deletion in
> ReorderBufferPassBaseSnapshot().
I've been going over this patch also, and I've made a few minor edits of
the patch and the existing code as I come to understand what it's all
about.
> Also I think it makes no harm if you split the diff into two, although both
> fixes use the by_base_snapshot_lsn field.
Please don't.
--
Álvaro Herrera https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
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To: pgsql-hackers@postgresql.org
Cc: alvherre@2ndquadrant.com, ah@cybertec.at, a.sher@postgrespro.ru
Subject: Re: Fix slot's xmin advancement and subxact's lost snapshots in decoding.
In-Reply-To: <20180618180419.mysc6nxvntgvfgg2@alvherre.pgsql>
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