From: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
To: Robert Haas <robertmhaas@gmail.com>
To: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Cc: Noah Misch <noah@leadboat.com>
Cc: PostgreSQL-development <pgsql-hackers@postgresql.org>
Cc: Dmitry Dolgov <9erthalion6@gmail.com>
Cc: Andrew Dunstan <andrew.dunstan@2ndquadrant.com>
Cc: hlinnaka <hlinnaka@iki.fi>
Cc: Michael Paquier <michael@paquier.xyz>
Subject: Re: [HACKERS] WAL logging problem in 9.4.3?
Date: Fri, 22 Nov 2019 13:21:31 +0100
Message-ID: <1f9a76fe-6f77-eb5f-9292-9b1c92f4f5bd@2ndquadrant.com> (raw)
In-Reply-To: <CA+TgmoYzTPpxvPUUs_ALW1YYNxV6mCrj6zwqnaN6FqdNc1JUzw@mail.gmail.com>
References: <20190828.154210.204505676.horikyota.ntt@gmail.com>
<20191025.131251.322449872063947371.horikyota.ntt@gmail.com>
<CAKPRHzJSgMuNeCtKgSxBJd2zOgK3BKL13Pkn_6_Sr9qXCRU=fQ@mail.gmail.com>
<CA+TgmoYzTPpxvPUUs_ALW1YYNxV6mCrj6zwqnaN6FqdNc1JUzw@mail.gmail.com>
On 2019-11-05 22:16, Robert Haas wrote:
> First, I'd like to restate my understanding of the problem just to see
> whether I've got the right idea and whether we're all on the same
> page. When wal_level=minimal, we sometimes try to skip WAL logging on
> newly-created relations in favor of fsync-ing the relation at commit
> time.
How useful is this behavior, relative to all the effort required?
Even if the benefit is significant, how many users can accept running
with wal_level=minimal and thus without replication or efficient backups?
Is there perhaps an alternative approach involving unlogged tables to
get a similar performance benefit?
--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
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To: pgsql-hackers@postgresql.org
Cc: peter.eisentraut@2ndquadrant.com, robertmhaas@gmail.com, horikyota.ntt@gmail.com, noah@leadboat.com, 9erthalion6@gmail.com, andrew.dunstan@2ndquadrant.com, hlinnaka@iki.fi, michael@paquier.xyz
Subject: Re: [HACKERS] WAL logging problem in 9.4.3?
In-Reply-To: <1f9a76fe-6f77-eb5f-9292-9b1c92f4f5bd@2ndquadrant.com>
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