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Re: Create and drop temp table in 8.3.4

From: "Kevin Grittner" <Kevin(dot)Grittner(at)wicourts(dot)gov>
To: <jd(at)commandprompt(dot)com>
Cc: <pgsql-performance(at)postgresql(dot)org>
Subject: Re: Create and drop temp table in 8.3.4
Date: 2008-11-06 19:35:26
Message-ID: 4912F29E.EE98.0025.0@wicourts.gov (view raw or flat)
Thread:
Lists: pgsql-performance
>>> "Joshua D. Drake" <jd(at)commandprompt(dot)com> wrote: 
> On Thu, 2008-11-06 at 13:02 -0600, Kevin Grittner wrote:
>> the new kernel
>> defaulted to using write barriers, while the old kernel didn't. 
Since
>> we have a BBU RAID controller, we will add nobarrier to the fstab
>> entries.  This makes file creation and unlink each about 20 times
>> faster.
> 
> Woah... which version of the kernel was old and new?
 
old:
 
kgrittn(at)DBUTL-PG:/var/pgsql/data/test> cat /proc/version
Linux version 2.6.5-7.287.3-bigsmp (geeko(at)buildhost) (gcc version 3.3.3
(SuSE Linux)) #1 SMP Tue Oct 2 07:31:36 UTC 2007
kgrittn(at)DBUTL-PG:/var/pgsql/data/test> uname -a
Linux DBUTL-PG 2.6.5-7.287.3-bigsmp #1 SMP Tue Oct 2 07:31:36 UTC 2007
i686 i686 i386 GNU/Linux
kgrittn(at)DBUTL-PG:/var/pgsql/data/test> cat /etc/SuSE-release
SUSE LINUX Enterprise Server 9 (i586)
VERSION = 9
PATCHLEVEL = 3
 
new:
 
kgrittn(at)SAWYER-PG:~> cat /proc/version
Linux version 2.6.16.60-0.27-smp (geeko(at)buildhost) (gcc version 4.1.2
20070115 (SUSE Linux)) #1 SMP Mon Jul 28 12:55:32 UTC 2008
kgrittn(at)SAWYER-PG:~> uname -a
Linux SAWYER-PG 2.6.16.60-0.27-smp #1 SMP Mon Jul 28 12:55:32 UTC 2008
x86_64 x86_64 x86_64 GNU/Linux
kgrittn(at)SAWYER-PG:~> cat /etc/SuSE-release
SUSE Linux Enterprise Server 10 (x86_64)
VERSION = 10
PATCHLEVEL = 2
 
To be clear, file create and unlink speeds are almost the same between
the two kernels without write barriers; the difference is that they
were in effect by default in the newer kernel.
 
-Kevin

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Next:From: Scott CareyDate: 2008-11-06 21:05:06
Subject: Re: Create and drop temp table in 8.3.4
Previous:From: Joshua D. DrakeDate: 2008-11-06 19:17:51
Subject: Re: Create and drop temp table in 8.3.4

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