Date: Thu, 27 Dec 2018 10:15:34 +0900
From: Michael Paquier <michael@paquier.xyz>
To: Fabien COELHO <coelho@cri.ensmp.fr>
Cc: Michael Banck <michael.banck@credativ.de>,
	Postgres hackers <pgsql-hackers@postgresql.org>
Subject: Re: Offline enabling/disabling of data checksums
Message-ID: <20181227011534.GD2106@paquier.xyz>
References: <20181221201616.GD4974@nighthawk.caipicrew.dd-dns.de>
 <alpine.DEB.2.21.1812261900400.32444@lancre>
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On Wed, Dec 26, 2018 at 07:43:17PM +0100, Fabien COELHO wrote:
>> It adds an (now mandatory) --action parameter that takes either verify,
>> enable or disable as argument.
>=20
> I'd rather have explicit switches for verify, enable & disable, and verify
> would be the default if none is provided.

Okay, noted for the separate switches.  But I don't agree with the
point of assuming that --verify should be enforced if no switches are
defined.  That feels like a trap for newcomers of this tool..

> For enable/disable, while the command is running, it should mark the clus=
ter
> as opened to prevent an unwanted database start. I do not see where this =
is
> done.

You have pretty much the same class of problems if you attempt to
start a cluster on which pg_rewind or the existing pg_verify_checksums
is run after these have scanned the control file to make sure that
they work on a cleanly-stopped instance.  In short, this is a deal
between code simplicity and trying to have the tool outsmart users in
the way users use the tool.  I tend to prefer keeping the code simple
and not worry about cases where the users mess up with their
application, as there are many more things which could go wrong.
--
Michael

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