Re: Re : Solaris Performance - Profiling (Solved)

Added to TODO:

    * Add BSD-licensed qsort() for Solaris

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Mark kirkwood wrote:
> On Wed, 2002-04-03 at 04:02, Tom Lane wrote:
>  >
> > Hmm.  Where exactly did you get those numbers from?  I see 4118.54 sec
> > as the total CPU accounted for in the profile.
> >
> odd ...the call graph has 4047.53 and the flat graph has 4118.54
> >
> > Hmm.  Assuming that the profile data is trustworthy and the queries are
> > indeed the same (did you compare EXPLAIN output?), it seems that
> > Solaris' problem is a spectacularly bad qsort() implementation.
> >
> A bit surfing finds heaps of unhappy Solaris qsort users... apparently
> it cannot sort lists with many repeated items... so our GROUP BY will be
> causing it grief here
> >
> > It might be entertaining to snarf a qsort off the net (from glibc,
> > perhaps) and link it into Postgres to see if you get better results.
> >
> >             regards, tom lane
> >
> Indeed it is - obtained qsort.c from Freebsd CVS and rebuilt Postgresql :
> The query now takes 6 seconds instead of 1 hour ! Thanks for an
> excellent suggestion.
>
> For those in need to a quick fix :
>
> I did a cheap and dirty mod to src/backend/utils/sort/Makefile
>
> changed OBJS = logtape.o -> OBJS = qsort.o logtape.o
>
> and copied qsort.c into this directory
>
> (had to comment out a couple of lines to compile under Solaris :
>
> /*#include <sys/cdefs.h>
> __FBSDID("$FreeBSD: src/lib/libc/stdlib/qsort.c,v 1.11 2002/03/22
> 21:53:10 obrien Exp $");
> */
>
> )
>
> What do you think about providing something like this for the Solaris
> port ? (since its clearly quicker...)
>
> regards
>
> Mark
>
>
>
>
>
>
>
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