Why would installing Oracle 10g decrease overall disk performance?

From: Wes Harrison <nospam_at_home.com>
Date: Thu, 25 Aug 2005 23:18:54 +1000
Message-ID: <430dc559$0$5409$5a62ac22@per-qv1-newsreader-01.iinet.net.au>

I am installing Oracle 10g 10.2.01 on Windows Server 2003 SP1 32-bit edition but for some strange reason the overall performance of the disks on the server decreases after it is installed. I know this because I am using SiSoft SANDRA Pro to do a File System Benchmark before and after the installation. Before, the drive index is about 80MB/S but this decreases by half after Oracle is installed. If I uninstall Oracle, the drive index returns to about 80. Reinstall Oracle and it goes back down to about 40.

No other package that I have installed on this server has had this effect. So I figured it must have something to do with fragmentation but the results are unchanged after a full defrag.

What could be causing this? Is it an error in the benchmark? Does it have something to do with some of the Oracle processes interfering with SANDRA Pro? It can't be just coincidence as I have repeated the test several times.

Thanks,

Wes Received on Thu Aug 25 2005 - 08:18:54 CDT