Re: [PATCH] Incremental sort
От | Alexander Korotkov |
---|---|
Тема | Re: [PATCH] Incremental sort |
Дата | |
Msg-id | CAPpHfdsGTgE69okyyXLN2Sq7FFosPtgzxDspA271rh=+8f7AZg@mail.gmail.com обсуждение исходный текст |
Ответ на | Re: [PATCH] Incremental sort (David Steele <david@pgmasters.net>) |
Ответы |
Re: [PATCH] Incremental sort
|
Список | pgsql-hackers |
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!
------
Alexander Korotkov
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company
Alexander Korotkov
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company
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