From: Tom Lane <tgl@sss.pgh.pa.us>
To: Michael Paquier <michael.paquier@gmail.com>
cc: Amit Kapila <amit.kapila16@gmail.com>,
        tushar <tushar.ahuja@enterprisedb.com>,
        PostgreSQL-development <pgsql-hackers@postgresql.org>
Subject: Re: pg_resetwal is broken if run from v10 against older version of PG
 data directory
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Comments: In-reply-to Michael Paquier <michael.paquier@gmail.com>
	message dated "Mon, 29 May 2017 09:55:26 -0700"
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Date: Mon, 29 May 2017 13:02:28 -0400
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Michael Paquier <michael.paquier@gmail.com> writes:
> On Mon, May 29, 2017 at 9:00 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> So we need to prevent this, not try to make it work.  I don't think
>> we can insist on a version match in pg_control, because part of the
>> point of pg_resetxlog/pg_resetwal is to recover if pg_control is
>> unreadable.  But I think we could look at PG_VERSION, which is only a
>> text file.

> Agreed. Shouldn't this be back-patched? PG_CONTROL_VERSION has not
> been bumped between 9.4 and 9.5. Attached is a patch for HEAD.

Yeah, I'm thinking it would be a good idea to enforce this in all
branches.  Your patch looks sane in a quick once-over, but I didn't
test it.

			regards, tom lane


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