Re: [PATCH] Incremental sort

From: Alexander Korotkov <a(dot)korotkov(at)postgrespro(dot)ru>
To: Andres Freund <andres(at)anarazel(dot)de>
Cc: David Steele <david(at)pgmasters(dot)net>, Heikki Linnakangas <hlinnaka(at)iki(dot)fi>, Mithun Cy <mithun(dot)cy(at)enterprisedb(dot)com>, Robert Haas <robertmhaas(at)gmail(dot)com>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: [PATCH] Incremental sort
Date: 2017-04-03 19:03:56
Message-ID: CAPpHfdtJEM9D3mp9tDXA2dHbNUAjF08rgnqAoTJwti2eH8qsFQ@mail.gmail.com
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On Mon, Apr 3, 2017 at 9:34 PM, Andres Freund <andres(at)anarazel(dot)de> wrote:

> On 2017-03-29 00:17:02 +0300, Alexander Korotkov wrote:
> > On Tue, Mar 28, 2017 at 5:27 PM, David Steele <david(at)pgmasters(dot)net>
> wrote:
> > > On 3/20/17 10:19 AM, Heikki Linnakangas wrote:
> > >
> > >> On 03/20/2017 11:33 AM, Alexander Korotkov wrote:
> > >>
> > >>> Please, find rebased patch in the attachment.
> > >>>
> > >>
> > >> I had a quick look at this.
> > >>
> > >
> > > <...>
> > >
> > > According to 'perf', 85% of the CPU time is spent in ExecCopySlot(). To
> > >> alleviate that, it might be worthwhile to add a special case for when
> > >> the group contains exactly one group, and not put the tuple to the
> > >> tuplesort in that case. Or if we cannot ensure that the Incremental
> Sort
> > >> is actually faster, the cost model should probably be smarter, to
> avoid
> > >> picking an incremental sort when it's not a win.
> > >>
> > >
> > > This thread has been idle for over a week. Please respond with a new
> > > patch by 2017-03-30 00:00 AoE (UTC-12) or this submission will be
> marked
> > > "Returned with Feedback".
>
> > Thank you for reminder!
>
> I've just done so. Please resubmit once updated, it's a cool feature.
>

Thank you!
I already sent version of patch after David's reminder.
Please find rebased patch in the attachment.

------
Alexander Korotkov
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company

Attachment Content-Type Size
incremental-sort-5.patch application/octet-stream 112.5 KB

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