Horton

Re: lastOverflowedXid does not handle transaction ID wraparound

Dmitry Dolgov <9erthalion6@gmail.com>

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From: Dmitry Dolgov <9erthalion6@gmail.com>
To: Andrey Borodin <x4mmm@yandex-team.ru>
Cc: Stan Hu <stanhu@gmail.com>, Pg Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2021-10-20T11:48:33Z
Lists: pgsql-hackers 
> On Wed, Oct 20, 2021 at 04:00:35PM +0500, Andrey Borodin wrote:
> > 17 окт. 2021 г., в 21:55, Dmitry Dolgov <9erthalion6@gmail.com> написал(а):
> > I wonder what would be side
> > effects of clearing it when the snapshot is not suboverfloved anymore?
>
> I think we should just invalidate lastOverflowedXid on every XLOG_RUNNING_XACTS if subxid_overflow == false. I can't find a reason not to do so.

From what I understand that was actually the case, lastOverflowedXid was
set to InvalidTransactionId in ProcArrayApplyRecoveryInfo if
subxid_overflow wasn't set. Looks like 10b7c686e52a6d1bb has changed it,
to what I didn't pay attention originally.

Commits

  1. Reset lastOverflowedXid on standby when needed

  2. Fix variable shadowing in procarray.c.

  3. Move InRecovery and standbyState global vars to xlogutils.c.