The best CPU usage measurement in Oracle: BUFFER_GETS or CPU_TIME?
- From: J.Velikanovs@xxxxxxxx
- To: oracle-l@xxxxxxxxxxxxx
- Date: Fri, 18 Jun 2004 10:47:54 +0300
My regards to all members,
Just would like to know your opinion.
Since 9i (suppose 9.2) we have CPU_TIME column in the V$SQL view.
I wonder which figure is the best measurement of CPU usage BUFFER_GETS or
CPU_TIME?
=======================================================
Lets imagine I have system with CPU bottleneck (can see height “load
average” from OS) for a 1-3 ours. No particular long sessions have been
executed. It is seams mainly OLTP system. Parse CPU usage not the issue.
I would like to identify TOP CPU consumers. As we all know I the V$SQL is
the best information source in this case.
=======================================================
I wonder which figure is the best measurement of CPU usage: BUFFER_GETS or
CPU_TIME? Statspack report, as well as Anjo Kolk www.oraperf.com
recommending to look on BUFFER_GETS not to CPU_TIME. Is it just tradition
or there are some arguments not to look on CPU_TIME as main CPU usage
indicator.
One reason I can imagine why CPU_TIME better indicator then BUFFER_GETS is
sorting. I can imagine that BUFFER_GETS not taking in account CPU spent to
sorting staff. Then from CPU usage perspective better indicator is
CPU_TIME.
Please correct me if I am wrong.
Thanks in advance,
Jurijs
Other related posts:
