From: Sven Geisler <sgeisler@aeccom.com>
To: Martijn van Oosterhout <kleptog@svana.org>
Cc: Florian Weimer <fw@deneb.enyo.de>
Cc: Neil Conway <neilc@samurai.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Gary Doades <gpd@gpdnet.co.uk>
Cc: pgsql-performance@postgresql.org
Cc: pgsql-hackers@postgresql.org
Subject: Re: [PERFORM] qsort again
Date: Thu, 16 Feb 2006 14:08:40 +0100
Message-ID: <43F47958.8000605@aeccom.com> (raw)
In-Reply-To: <20060216124918.GE26127@svana.org>
References: <43F38867.6010701@gpdnet.co.uk>
<19510.1140036968@sss.pgh.pa.us>
<19779.1140038874@sss.pgh.pa.us>
<43F39E53.1020009@gpdnet.co.uk>
<20781.1140046109@sss.pgh.pa.us>
<1140055972.31672.42.camel@localhost.localdomain>
<873bijsdvb.fsf@mid.deneb.enyo.de>
<20060216124918.GE26127@svana.org>
Martijn van Oosterhout schrieb:
>
> Last time around there were a number of different algorithms tested.
> Did anyone run those tests while getting it to count the number of
> actual comparisons (which could easily swamp the time taken to do the
> actual sort in some cases)?
>
The last time I did such tests is almost 10 years ago. I had used
MetroWerks CodeWarrior C/C++, which had Quicksort as algorithm in the Lib C.
Anyhow, I tested a few algorithms including merge sort and heapsort. I
end up with heapsort because it was the fastest algorithm for our issue.
We joined two arrays where each array was sorted and run qsort to sort
the new array.
Sven.
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To: pgsql-performance@postgresql.org
Cc: sgeisler@aeccom.com, kleptog@svana.org, fw@deneb.enyo.de, neilc@samurai.com, tgl@sss.pgh.pa.us, gpd@gpdnet.co.uk, pgsql-hackers@postgresql.org
Subject: Re: [PERFORM] qsort again
In-Reply-To: <43F47958.8000605@aeccom.com>
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