From: Martijn van Oosterhout <kleptog@svana.org>
To: Simon Riggs <simon@2ndquadrant.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Ron Peacetree <rjpeace@earthlink.net>
Cc: pgsql-hackers@postgresql.org
Subject: Re: [PERFORM] A Better External Sort?
Date: Tue, 4 Oct 2005 14:24:46 +0200
Message-ID: <20051004122443.GF17589@svana.org> (raw)
In-Reply-To: <1128425094.8603.296.camel@localhost.localdomain>
References: <18329659.1128188552696.JavaMail.root@elwamui-polski.atl.sa.earthlink.net>
<20051001215602.GG13830@svana.org>
<29837.1128223567@sss.pgh.pa.us>
<20051002123240.GA30492@svana.org>
<20051002193835.GJ30492@svana.org>
<1128376292.8603.142.camel@localhost.localdomain>
<20051004100441.GC17589@svana.org>
<1128425094.8603.296.camel@localhost.localdomain>
On Tue, Oct 04, 2005 at 12:24:54PM +0100, Simon Riggs wrote:
> How did you determine the 1500 figure? Can you give some more info to
> surround that recommendation to allow everybody to evaluate it?
kleptog@vali:~/dl/cvs/pgsql-local/src/backend/utils/sort$ gcc -finline-limit-1000 -Winline -O2 -Wall -Wmissing-prototypes -Wpointer-arith -Wendif-labels -fno-strict-aliasing -g -I../../../../src/include -D_GNU_SOURCE -c -o tuplesort.o tuplesort.c
tuplesort.c: In function 'applySortFunction':
tuplesort.c:1833: warning: inlining failed in call to 'inlineApplySortFunction'
tuplesort.c:1906: warning: called from here
tuplesort.c: In function 'comparetup_heap':
tuplesort.c:1833: warning: inlining failed in call to 'inlineApplySortFunction'
tuplesort.c:1937: warning: called from here
tuplesort.c: In function 'comparetup_index':
tuplesort.c:1833: warning: inlining failed in call to 'inlineApplySortFunction'
tuplesort.c:2048: warning: called from here
tuplesort.c: In function 'comparetup_datum':
tuplesort.c:1833: warning: inlining failed in call to 'inlineApplySortFunction'
tuplesort.c:2167: warning: called from here
kleptog@vali:~/dl/cvs/pgsql-local/src/backend/utils/sort$ gcc -finline-limit-1500 -Winline -O2 -Wall -Wmissing-prototypes -Wpointer-arith -Wendif-labels -fno-strict-aliasing -g -I../../../../src/include -D_GNU_SOURCE -c -o tuplesort.o tuplesort.c
<no warnings>
A quick binary search puts the cutoff between 1200 and 1300. Given
version variation I picked a nice round number, 1500.
Ugh, that's for -O2, for -O3 and above it needs to be 4100 to work.
Maybe we should go for 5000 or so.
I'm using: gcc (GCC) 3.3.5 (Debian 1:3.3.5-13)
Have a nice day,
--
Martijn van Oosterhout <kleptog@svana.org> http://svana.org/kleptog/> Patent. n. Genius is 5% inspiration and 95% perspiration. A patent is a
> tool for doing 5% of the work and then sitting around waiting for someone
> else to do the other 95% so you can sue them.
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To: pgsql-performance@postgresql.org
Cc: kleptog@svana.org, simon@2ndquadrant.com, tgl@sss.pgh.pa.us, rjpeace@earthlink.net, pgsql-hackers@postgresql.org
Subject: Re: [PERFORM] A Better External Sort?
In-Reply-To: <20051004122443.GF17589@svana.org>
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