From: Tom Lane <tgl@sss.pgh.pa.us>
To: Craig Ringer <craig@2ndquadrant.com>
cc: Robert Haas <robertmhaas@gmail.com>,
        Abhijit Menon-Sen <ams@2ndquadrant.com>,
        Andres Freund <andres@anarazel.de>,
        Simon Riggs <simon@2ndquadrant.com>,
        Petr Jelinek <petr@2ndquadrant.com>,
        Magnus Hagander <magnus@hagander.net>,
        "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Subject: Re: 9.6 and fsync=off
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Comments: In-reply-to Craig Ringer <craig@2ndquadrant.com>
	message dated "Mon, 02 May 2016 22:27:08 +0800"
Date: Mon, 02 May 2016 10:32:44 -0400
Message-ID: <20364.1462199564@sss.pgh.pa.us>
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Craig Ringer <craig@2ndquadrant.com> writes:
> On 2 May 2016 at 22:07, Robert Haas <robertmhaas@gmail.com> wrote:
>> I also think that it would be a swell idea to detect whether a system
>> has ever crashed with fsync=off, and do something about that, like
>> maybe bleat on every subsequent startup for the lifetime of the
>> cluster.

> Yes. Very, very yes.

+1 for tracking this in pg_control (maybe even with a counter, not
just a flag).  I'm less convinced that we need to bleat on every
subsequent startup though --- that seems like just nagging.
Having the info available from pg_controldata seems sufficient for
forensics.

The timestamp ideas aren't bad either.

BTW, how would this work in a standby server?

			regards, tom lane


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