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Home -> Community -> Mailing Lists -> Oracle-L -> RE: How accurate is ADDM?
Hey Paul,
Yes, for the time period in question, the average log file sync is 944ms and log file parallel write is 3020ms.
A couple of other write wait events:
Db file parallel write = 529
Control file parallel write = 1887
We are in a SAN environment. So we have been presented with one LUN. Underneath its Raid 0+1 with 30 or so disks.
-----Original Message-----
From: Baumgartel, Paul [mailto:paul.baumgartel_at_credit-suisse.com]
Sent: Tuesday, December 04, 2007 4:09 PM
To: Best, David; oracle-l_at_freelists.org
Subject: RE: How accurate is ADDM?
Have you confirmed the write time by generating an AWR report for that time period and seeing what the average wait for log file parallel write and log file sync is?
Paul Baumgartel
CREDIT SUISSE
Information Technology
Securities Processing Databases Americas One Madison Avenue New York, NY
10010 USA Phone 212.538.1143 paul.baumgartel_at_credit-suisse.com
www.credit-suisse.com
-----Original Message-----
From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Best, David
Sent: Tuesday, December 04, 2007 3:21 PM
To: oracle-l_at_freelists.org
Subject: How accurate is ADDM?
Hey all,
How accurate is ADDM? Today we had a severe performance issue with one our of databases. The ADDM recommendation for that period put the most weight on the following:
---[ADDM Snip]---
Action Investigate the possibility of improving the performance of I/O
to the online redo log files.
Rationale The average size of writes to the online redo log files was
932 K and the average time per write was 3020 milliseconds.
---[ADDM Snip]---
The problem is, our storage team doesn't see the same level of degredation. Any suggestions?
tnx
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Received on Tue Dec 04 2007 - 16:03:05 CST
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