Re: qsort again (was Re: [PERFORM] Strange Create Index

From: Neil Conway <neilc(at)samurai(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: Gary Doades <gpd(at)gpdnet(dot)co(dot)uk>, pgsql-performance(at)postgresql(dot)org, pgsql-hackers(at)postgresql(dot)org
Subject: Re: qsort again (was Re: [PERFORM] Strange Create Index
Date: 2006-02-16 02:12:52
Message-ID: 1140055972.31672.42.camel@localhost.localdomain
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On Wed, 2006-02-15 at 18:28 -0500, Tom Lane wrote:
> It seems clear that our qsort.c is doing a pretty awful job of picking
> qsort pivots, while glibc is mostly managing not to make that mistake.
> I haven't looked at the glibc code yet to see what they are doing
> differently.

glibc qsort is actually merge sort, so I'm not surprised it avoids this
problem.

-Neil

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