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Donald K. Burleson Oracle Tips |
Find Oracle segment header contention
However, segment header contention will still occur when concurrent tasks attempt to INSERT into the same table, and multiple freelists are required to remove these sources of buffer busy waits.
If you are using Oracle9i and above, you also have a way of finding out what objects have been the source of buffer busy waits. The bufobjwaits.sql script will tell you everything you need to know:
See Code depot for complete script
select owner, object_name, . . .from sys.v$segment_statistics
where (statistic_name = 'buffer busy waits' and value > 0) order by 1,2; OWNER OBJECT_NAME OBJECT_TYPE WAITS -------------------------------------------- USR1 TAB1 TABLE 3 USR1 TAB2 TABLE 2 USR1 TAB3 TABLE 2
The above is an excerpt from Oracle Performance Troubleshooting by Robin Schumacher.
It's only $19.95 and you can order it and get instant access to the Oracle scripts here:
http://www.rampant-books.com/book_2003_1_perf.htm
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email BC:
Copyright © 1996 - 2010 by Burleson Enterprises, Inc. All
rights reserved. Oracle® is the registered trademark of Oracle Corporation.
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