On Mon, Apr 3, 2017 at 10:05 PM, Andres Freund <andres@anarazel.de> wrote:
On April 3, 2017 12:03:56 PM PDT, Alexander Korotkov <a.korotkov@postgrespro.ru> wrote: >On Mon, Apr 3, 2017 at 9:34 PM, Andres Freund <andres@anarazel.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@pgmasters.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.
Cool. I think that's still a bit late for v10?
I don't know. ISTM, that I addressed all the issues raised by reviewers.
Also, this patch is pending since late 2013. It would be very nice to finally get it in...
------ Alexander Korotkov Postgres Professional: http://www.postgrespro.com The Russian Postgres Company
