Message-ID: <65e4f3684f7563acc8b309393b8e14388b5eae0d.camel@oopsware.de>
Subject: Re: Offline enabling/disabling of data checksums
From: Bernd Helmle <mailings@oopsware.de>
To: Fabien COELHO <coelho@cri.ensmp.fr>, Michael Banck
	 <michael.banck@credativ.de>
Cc: Magnus Hagander <magnus@hagander.net>, Michael Paquier
 <michael@paquier.xyz>,  Postgres hackers <pgsql-hackers@postgresql.org>
Date: Tue, 08 Jan 2019 15:39:30 +0100
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	  <20181227011534.GD2106@paquier.xyz>
	  <CABUevEwbPVR_6Uv4D44fCd9tB_=aFxG4awUx+DJawD8_speuCA@mail.gmail.com>
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Am Dienstag, den 08.01.2019, 15:09 +0100 schrieb Fabien COELHO:
> > The question is how to reliably do this in an acceptable way? Just
> > faking a postmaster.pid sounds pretty hackish to me, do you have
> > any
> > suggestions here?
> 
> Adding a new state to ControlFileData which would prevent it from 
> starting?

But then you have to make sure the control flag gets cleared in any
case pg_verify_checksums crashes somehow or gets SIGKILL'ed ...

Setting the checksum flag is done after having finished all blocks, so
there is no problem. But we need to set this new flag before and reset
it afterwards, so in between strange things can happen (as the various
calls to exit() within error handling illustrates). 

Bernd.