Horton

Re: Explain buffers wrong counter with parallel plans

Amit Kapila <amit.kapila16@gmail.com>

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From: Amit Kapila <amit.kapila16@gmail.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Andres Freund <andres@anarazel.de>, "Jonathan S. Katz" <jonathan.katz@excoventures.com>, Alvaro Herrera <alvherre@2ndquadrant.com>, Adrien Nayrat <adrien.nayrat@anayrat.info>, PostgreSQL mailing lists <pgsql-hackers@postgresql.org>
Date: 2018-08-13T03:52:20Z
Lists: pgsql-hackers 
On Sun, Aug 5, 2018 at 5:34 PM, Amit Kapila <amit.kapila16@gmail.com> wrote:
> On Fri, Aug 3, 2018 at 2:09 PM, Amit Kapila <amit.kapila16@gmail.com> wrote:
>> On Thu, Aug 2, 2018 at 11:14 PM, Robert Haas <robertmhaas@gmail.com> wrote:
>>>  In the third one, I don't think
>>> "See ExecLimit" is a good thing to put a comment like this, because
>>> it's too hard to find the comment to which it refers, and because
>>> future commits are likely to edit or remove that comment without
>>> noticing the references to it from elsewhere.  Instead I would just
>>> write, in all three places, /* If we know we won't need to back up, we
>>> can release resources at this point. */ or something like that.
>>>
>>
>> Okay, I have changed the comment as per your suggestion in the
>> attached patch.  I will do some more testing/verification of this
>> patch and will commit over the weekend or on Monday if everything is
>> fine.
>>
>
> I have verified that the patch works whenever we use scrollable
> cursors.  Please find the attached patch with the modified commit
> message.  I think now it is a bit late for this minor-release and this
> doesn't appear to be a blocker issue, it is better to push it after
> the release.
>

Pushed.

-- 
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com

Commits

  1. Adjust comment atop ExecShutdownNode.

  2. Prohibit shutting down resources if there is a possibility of back up.

  3. Fix buffer usage stats for parallel nodes.

  4. Match the buffer usage tracking for leader and worker backends.

  5. Improve division of labor between execParallel.c and nodeGather[Merge].c.