Not only that, but if your "disk" is really a bunch of disks behind a hardware RAID controller, or SAN, or iSCSI or
NFSserver - what is contiguous for the OS may not be contiguous on the physical drives (and vice versa). <br /> Which
iswhy performance can (but may not) improve if you disable linux kernel IO schedulers that attempt to optimize blocks
tobe 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 /><div class="moz-signature">-- <br /><style type="text/css"> .sig, .sig a, .sig td {
font:12px Arial; color: DarkBlue; white-space: nowrap; vertical-align: top; text-align: left; } .sig img { border: 0; }
.siga { font: 11px Arial; } .sig .back { color: #ffffff; background-color: DarkBlue; text-decoration: none; } .sig
.right{ text-align: right; } .sig .border { border: 1px solid DarkBlue; margin:5px; border-collapse: collapse; } .sig
.bottom{ vertical-align:bottom } .sig p { clear:both; margin:2px; } </style><div class="sig"><table
class="border"><tbody><tr><tdclass="back"> <b>Steve Francis</b></td><td class="back" style="width: 30px;"><br
/></td><tdclass="back" style="text-align: right;"><b>LogicMonitor LLC</b></td></tr><tr><td><br /></td><td><br
/></td><tdclass="right"><br /></td></tr><tr><td class="bottom"><a class="moz-txt-link-abbreviated"
href="mailto:sfrancis@logicmonitor.com">sfrancis@logicmonitor.com</a><br/><a href="http://www.logicmonitor.com"
target="_blank">www.logicmonitor.com</a></td><td><br/></td><td class="bottom" style="text-align: right;"> Ph: 1 888 41
LOGICx500<br /> Ph: 1 805 698 0770</td></tr></tbody></table><p> <br /></div></div>