Re: qsort (was Re: Solaris)

From: Mark Kirkwood <markir(at)paradise(dot)net(dot)nz>
To: Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
Cc: Mike Castle <dalgoda(at)ix(dot)netcom(dot)com>, pgsql-general(at)postgresql(dot)org
Subject: Re: qsort (was Re: Solaris)
Date: 2003-06-01 23:51:11
Message-ID: 3EDA916F.5050109@paradise.net.nz
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That is probably the most reasonable conclusion to draw from the results ;-)

cheers

Mark

Bruce Momjian wrote:

>I assume we decided that BSD sort isn't fast enough to warrant replacing
>the native qsort.
>
>---------------------------------------------------------------------------
>
>Mark Kirkwood wrote:
>
>
>>Mike Castle wrote:
>>
>>
>>
>>>First I added a counter to the compare function, and the most cases, the
>>>glibc implementation was called significantly less often than the BSD
>>>compare function.
>>>
>>>
>>>
>>>
>>Interesting - all examples I tried had glibc compare count higher, do
>>you want to post one of yours?
>>
>>
>>
>>>In a simple test function, like comparing two ints, then yes, the BSD
>>>implementation was faster. But in a more complex function, say comparing
>>>strings, often times the glibc version was faster. Why? Because the
>>>time spent in the compare function became the overwhelming factor.
>>>
>>>
>>>
>>>
>>Considering strings is a good point - I went away and tried some
>>examples, unfortunately I only managed to see BSD faster, but the
>>difference was not as large as in the integer tests.
>>
>>
>>regards
>>
>>Mark
>>
>>
>>---------------------------(end of broadcast)---------------------------
>>TIP 6: Have you searched our list archives?
>>
>>http://archives.postgresql.org
>>
>>
>>
>
>
>

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