Oracle Release 10.2.0.3
Problem CPU and Performance
Top 5 Wait Events
You can find 'db file sequential read' and 'read by other session' apart from CPU as TOP 5Events. Based on the 'db file sequential read' it is evident that the system is using most of the indexes.
Once we go to the other wait event 'read by other session' which is nothing but buffer busy waits where information is requested from the database, Oracle will first read the data from disk into the database buffer cache. If two or more sessions request the same information, the first session will read the data into the buffer cache while other sessions wait; e.g. many sessions scanning the same index or performing full-table scans on the same table. Tuning this issue is a matter of finding and eliminating this contention.
So to figure which object is causing the contention, you can look at which tablespace/datafile has got buffer waits and which object is falling under the Segments by Physical Reads and Logical Reads. Based out which we have identified an index which is the cause for this contention. The same has been rebuild on to a different tablespace to reduce the contention.
You can get free tuning advices from our DB experts by simply sending mail to tuning@orakhoj.com
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