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".
--
-David
da...@pgmasters.net
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