From: Steve Francis <sfrancis@logicmonitor.com>
To: pgsql-admin@postgresql.org
Subject: Re: Pre-Allocate tablespace on disk
Date: Fri, 19 Nov 2010 11:42:44 -0800
Message-ID: <4CE6D334.6080005@logicmonitor.com> (raw)
In-Reply-To: <82zkt55ux4.fsf@mid.bfk.de>
References: <9CB65F11-6FA4-48D5-BCC5-B3F694659965@ruprecht.org>
<82zkt55ux4.fsf@mid.bfk.de>
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Not only that, but if your "disk" is really a bunch of disks behind
a hardware RAID controller, or SAN, or iSCSI or NFS server - what is
contiguous for the OS may not be contiguous on the physical drives
(and vice versa). <br>
Which is why performance can (but may not) improve if you disable
linux kernel IO schedulers that attempt to optimize blocks to be
sequential.<br>
<br>
<br>
<br>
On 11/19/2010 5:01 AM, Florian Weimer wrote:
<blockquote cite="mid:82zkt55ux4.fsf@mid.bfk.de" type="cite">
<pre wrap="">* Chris Ruprecht:
</pre>
<blockquote type="cite">
<pre wrap="">Other database that I have worked with before and that I'm still
working with, allow you to pre-allocate disk space so you get huge
chunks of contiguous space at one, which has major impacts on
database performance.
</pre>
</blockquote>
<pre wrap="">
PostgreSQL's write patterns do not trigger significant fragmentation
with most file systems, even when other database systems (Oracle
Berkeley DB comes to my mind) would create heavily fragmented files.
</pre>
</blockquote>
<br>
<br>
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<td class="back"> <b>Steve Francis</b></td>
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<td class="back" style="text-align: right;"><b>LogicMonitor
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To: pgsql-admin@postgresql.org
Cc: sfrancis@logicmonitor.com
Subject: Re: Pre-Allocate tablespace on disk
In-Reply-To: <4CE6D334.6080005@logicmonitor.com>
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