On Mon, Apr 3, 2017 at 10:05 PM, Andres Freund <and...@anarazel.de> wrote:
> On April 3, 2017 12:03:56 PM PDT, Alexander Korotkov < > a.korot...@postgrespro.ru> wrote: > >On Mon, Apr 3, 2017 at 9:34 PM, Andres Freund <and...@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 <da...@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
