Re: Parallel tuplesort (for parallel B-Tree index creation) - Mailing list pgsql-hackers

From Peter Geoghegan
Subject Re: Parallel tuplesort (for parallel B-Tree index creation)
Date
Msg-id CAM3SWZSCGz-nWEmEZTPVu-0SYdSRQwVLXo=bowtVgoP=CcY3Vg@mail.gmail.com
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In response to Re: Parallel tuplesort (for parallel B-Tree index creation)  (Peter Geoghegan <pg@heroku.com>)
Responses Re: Parallel tuplesort (for parallel B-Tree index creation)  (Heikki Linnakangas <hlinnaka@iki.fi>)
List pgsql-hackers
On Tue, Sep 6, 2016 at 12:39 PM, Peter Geoghegan <pg@heroku.com> wrote:
> On Tue, Sep 6, 2016 at 12:08 AM, Heikki Linnakangas <hlinnaka@iki.fi> wrote:
>>> I attach a patch that changes how we maintain the heap invariant
>>> during tuplesort merging.
>
>> Nice!
>
> Thanks!

BTW, the way that k-way merging is made more efficient by this
approach makes the case for replacement selection even weaker than it
was just before we almost killed it. I hate to say it, but I have to
wonder if we shouldn't get rid of the new-to-9.6
replacement_sort_tuples because of this, and completely kill
replacement selection. I'm not going to go on about it, but that seems
sensible to me.


-- 
Peter Geoghegan



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