Re: PoC: Partial sort - Mailing list pgsql-hackers

From Alexander Korotkov
Subject Re: PoC: Partial sort
Date
Msg-id CAPpHfdsHVEkg4p7P5V5uB6FeEjCKGc0hci4TZ9_kQCnHcvO5Kw@mail.gmail.com
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In response to Re: PoC: Partial sort  (Marti Raudsepp <marti@juffo.org>)
Responses Re: PoC: Partial sort  (Marti Raudsepp <marti@juffo.org>)
Re: PoC: Partial sort  (Peter Geoghegan <pg@heroku.com>)
Re: PoC: Partial sort  (David Rowley <dgrowleyml@gmail.com>)
List pgsql-hackers
On Mon, Feb 10, 2014 at 2:33 PM, Marti Raudsepp <marti@juffo.org> wrote:
On Sun, Feb 9, 2014 at 7:37 PM, Alexander Korotkov <aekorotkov@gmail.com> wrote:
> This is not only place that worry me about planning overhead. See
> get_cheapest_fractional_path_for_pathkeys. I had to estimate number of
> groups for each sorting column in order to get right fractional path.

AFAICT this only happens once per plan and the overhead is O(n) to the
number of pathkeys? I can't get worried about that, but I guess it's
better to test anyway.

PS: You didn't answer my questions about splitting the patch. I guess
I'll have to do that anyway to run the tests.

Done. Patch is splitted.

------
With best regards,
Alexander Korotkov.  
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