From: Tom Lane <tgl@sss.pgh.pa.us>
To: Jeff Davis <pgsql@j-davis.com>
Cc: Joshua D. Drake <jd@commandprompt.com>
Cc: CAJ CAJ <pguser@gmail.com>
Cc: Ralph Mason <ralph.mason@telogis.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Performance Woes
Date: Thu, 10 May 2007 00:30:04 -0400
Message-ID: <6685.1178771404@sss.pgh.pa.us> (raw)
In-Reply-To: <1178757739.24902.78.camel@dogma.v10.wvs>
References: <5132236932388612597@unknownmsgid>
<467669b30705091726j31fce52fp2f49649be675d811@mail.gmail.com>
<4642677F.80209@commandprompt.com>
<1178757739.24902.78.camel@dogma.v10.wvs>
Jeff Davis <pgsql@j-davis.com> writes:
> On Wed, 2007-05-09 at 17:29 -0700, Joshua D. Drake wrote:
>> Sounds to me like you just need to up the total amount of open files
>> allowed by the operating system.
> It looks more like the opposite, here's the docs for
> max_files_per_process:
I think Josh has got the right advice. The manual is just saying that
you can reduce max_files_per_process to avoid the failure, but it's not
making any promises about the performance penalty for doing that.
Apparently Ralph's app needs a working set of between 800 and 1000 open
files to have reasonable performance.
> That is a lot of tables. Maybe a different OS will handle it better?
> Maybe there's some way that you can use fewer connections and then the
> OS could still handle it?
Also, it might be worth rethinking the database structure to reduce the
number of tables. But for a quick-fix, increasing the kernel limit
seems like the easiest answer.
regards, tom lane
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Subject: Re: Performance Woes
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