Horton

Re: Reset snapshot export state on the transaction abort

Michael Paquier <michael@paquier.xyz>

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From: Michael Paquier <michael@paquier.xyz>
To: Dilip Kumar <dilipbalaut@gmail.com>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2021-10-14T06:54:29Z
Lists: pgsql-hackers 
On Wed, Oct 13, 2021 at 10:53:24AM +0530, Dilip Kumar wrote:
> Actually, it is not required because 1) Snapshot export can not be
> allowed within a transaction block, basically, it starts its own
> transaction block and aborts that while executing any next replication
> command see SnapBuildClearExportedSnapshot().  So our problem is only
> if the transaction block internally started for exporting, gets
> aborted before any next command arrives.  So there is no possibility
> of starting any sub transaction.

Yes, you are right here.  I did not remember the semantics this relies
on.  I have played more with the patch, reviewed the whole, and the
fields you are resetting as part of the snapshot builds seem correct
to me.  So let's fix this.
--
Michael

Commits

  1. Reset properly snapshot export state during transaction abort