RE: OS Paging/performance question

Are you measuring "memory allocated" based on the SGA alone? Or are you adding in all the PGA's as well? Batch processing implies DSS, which means that your SGA's may end up being larger than your PGA's. Do you have a PGA_AGGREGATE_TARGET defined?

Justin Cave <jcave_at_ddbcinc.com>
Distributed Database Consulting, Inc.
http://www.ddbcinc.com/askDDBC

-----Original Message-----

From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Ed
Sent: Tuesday, September 21, 2004 11:01 AM To: oracle-l_at_freelists.org
Subject: OS Paging/performance question

Looking for some advice here.

Windows 2000
Oracle 9.2.0.4

We are running several instances on the machine, but the memory allocated to them is far under the RAM available. ie. I shouldn't be OS paging as far as I can tell. I have even shut down instances to reduce the Oracle memory demands to much less than half the machine's RAM (4 gig total RAM), but I'm still paging like crazy.

Nonetheless, Windows Performance Monitor shows "pages/sec" going as high as 1500 sometimes when large batch jobs are running against the database. Jobs that used to run in 4 hours now run over 24 and sometimes fail.

In addition, I have massive "db file sequential read" wait events in the database doing the large batch jobs, but my DB Cache Hit Ratios are over 90%. I don't think Oracle's tuning utilities are going to help me figure this one out. Any ideas? Hopefully I'm just missing something very obvious.

The OS paging in particular is really bothering me!

Thanks in advance for your time.

Edward Simmonds

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http://www.freelists.org/webpage/oracle-l Received on Tue Sep 21 2004 - 10:04:41 CDT