Re: Re: Using quicksort and a merge step to significantly improve on tuplesort's single run "external sort"

From: Jeremy Harris <jgh(at)wizmail(dot)org>
To: pgsql-hackers(at)postgresql(dot)org
Subject: Re: Re: Using quicksort and a merge step to significantly improve on tuplesort's single run "external sort"
Date: 2015-08-01 13:49:44
Message-ID: 55BCCE78.8060206@wizmail.org
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On 31/07/15 18:31, Robert Haas wrote:
> On Fri, Jul 31, 2015 at 7:21 AM, Jeremy Harris <jgh(at)wizmail(dot)org> wrote:
>> Heapification is O(n) already, whether siftup (existing) or down.
>
> That's not my impression, or what Wikipedia says. Source?

Measurements done last year:

http://www.postgresql.org/message-id/52F35462.3030306@wizmail.org
(spreadsheet attachment)

http://www.postgresql.org/message-id/52F40CE9.1070509@wizmail.org
(measurement procedure and spreadsheet explanation)

--
Cheers,
Jeremy

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