Message-ID: <4491C330.5020104@kaltenbrunner.cc>
Date: Thu, 15 Jun 2006 22:29:36 +0200
From: Stefan Kaltenbrunner <stefan@kaltenbrunner.cc>
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To: Bruce Momjian <pgman@candle.pha.pa.us>
CC: pgsql-hackers@postgreSQL.org
Subject: Re: Test request for Stats collector performance improvement
References: <200606150405.k5F45cH11445@candle.pha.pa.us>
In-Reply-To: <200606150405.k5F45cH11445@candle.pha.pa.us>
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Bruce Momjian wrote:
> Would some people please run the attached test procedure and report back
> the results?  I basically need to know the patch is an improvement on
> more platforms than just my own.  Thanks


Debian Sarge/AMD64 Kernel 2.6.16.16 (all tests done multiple times with
variation of less then 10%):

-HEAD:

real    0m0.486s
user    0m0.064s
sys     0m0.048s

-HEAD with 100000 "SELECT 1;" queries:

real    0m4.763s
user    0m0.896s
sys     0m1.232s

-HEAD + stats:


real    0m0.720s
user    0m0.128s
sys     0m0.096s


-HEAD + stats (100k):


real    0m7.204s
user    0m1.504s
sys     0m1.028s


-HEAD + stats + patch:

there is something weird going on here - I get either runtimes like:

real    0m0.729s
user    0m0.092s
sys     0m0.100s

and occasionally:


real    0m3.926s
user    0m0.144s
sys     0m0.140s


(always ~0,7 vs ~4 seconds - same variation as Qingqing Zhou seems to see)


-HEAD + stats + patch(100k):

similiar variation with:

real    0m7.955s
user    0m1.124s
sys     0m1.164s

and

real    0m11.836s
user    0m1.368s
sys     0m1.156s

(ie 7-8 seconds vs 11-12 seconds)


looks like this patch is actually a loss on that box.


Stefan