Re: CPU Per Exec - SQL Ordered By CPU Time
- From: Laimutis.Nedzinskas@xxxxxx
- To: Oracle-L@xxxxxxxxxxxxx
- Date: Thu, 25 Nov 2010 10:20:01 +0200
Recently we've seen (in AWR)
db_time >> wait_times + cpu_time
where >> stands for "Much Bigger"
After some considerations we decided it can be either queueing or paging.
It turned out to be paging.
v$/dba_hist_osstat helped too.
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Harel Safra
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Subject
Re: CPU Per Exec - SQL Ordered By
2010.11.24 19:47 CPU Time
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harel.safra@gmail
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It probably includes the time the process was in the run queue but not on
the CPU itself (cpu wait).
Do you have matching OS statistics for the peak load? I'd look at CPU
utilization and run queue length.
Harel Safra
On 24/11/2010 19:03, Oracle Dba Wannabe wrote:
Hi,
With reference to AWR reports, during non peak and peak times I see
the following:
Non Peak:
|------------+--------------+----------+---------------+---------------+-------------+-+-|
|CPU Time (s)| Elapsed Time |Executions| CPU per Exec | % Total DB | SQL
Id | | |
| | (s) | | (s) | Time) |
| | |
|------------+--------------+----------+---------------+---------------+-------------+-+-|
| 1,092| 1,337| 28,730| 0.04|
6.51|3kmnk9f1htbcc| | |
|------------+--------------+----------+---------------+---------------+-------------+-+-|
Peak:
|------------+--------------+----------+---------------+---------------+-------------+-+-|
|CPU Time (s)| Elapsed Time |Executions| CPU per Exec |% Total DB Time| SQL
Id | | |
| | (s) | | (s) | |
| | |
|------------+--------------+----------+---------------+---------------+-------------+-+-|
| 4,679| 15,653| 29,922| 0.16|
6.05|3kmnk9f1htbcc| | |
|------------+--------------+----------+---------------+---------------+-------------+-+-|
I'm wondering what would cause the CPU per Exec to be greater during
the Peak time? I understand that its CPU Time/Executions.
Does CPU time include wait for CPU time too? which would mean during
the peak time since the system was overloaded or CPU bound we would
expect to see CPU per exec increase for the same statement?
Thanks
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