Horton

Re: pg_resetwal is broken if run from v10 against older version of PG data directory

Michael Paquier <michael.paquier@gmail.com>

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From: Michael Paquier <michael.paquier@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Amit Kapila <amit.kapila16@gmail.com>, tushar <tushar.ahuja@enterprisedb.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2017-05-29T17:05:14Z
Lists: pgsql-hackers 
On Mon, May 29, 2017 at 10:02 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> 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.

Thanks. I can provide patches for back-branches as needed.
-- 
Michael

Commits

  1. Prevent running pg_resetwal/pg_resetxlog against wrong-version data dirs.

  2. Rename "pg_xlog" directory to "pg_wal".