Re: [PATCH] Incremental sort - Mailing list pgsql-hackers

From Andres Freund
Subject Re: [PATCH] Incremental sort
Date
Msg-id 20170403183438.5matptjo6xhghpnu@alap3.anarazel.de
Whole thread Raw
In response to Re: [PATCH] Incremental sort  (Alexander Korotkov <a.korotkov@postgrespro.ru>)
List pgsql-hackers
On 2017-03-29 00:17:02 +0300, Alexander Korotkov wrote:
> On Tue, Mar 28, 2017 at 5:27 PM, David Steele <david@pgmasters.net> wrote:
> 
> > Hi Alexander,
> >
> > 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.

- Andres



pgsql-hackers by date:

Previous
From: Andres Freund
Date:
Subject: Re: [PATCH v.7] Move all am-related reloption code intosrc/backend/access/[am-name] and get rid of relopt_kind for custom AM
Next
From: Andres Freund
Date:
Subject: Re: SERIALIZABLE with parallel query