Re: CPU Time

Jonathan,

Thanks for the correction.

Only my question was, why CPU time appears in the top 5 timed events as 91% and the rest timed events are just 9%. for your information, statspack snap elapsed time was 1 hr. When I use response time formula, CPU Recursive show around 80% from my statspack report. I tried to look for the SQL order by gets from my statspack report. I just wanted to confirm, I am at the current place or not to identified resource consuming queries.

On Sun, 9 Jan 2005 15:01:40 -0000, Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk> wrote:
>
> The question is almost meaningless.
>
> Note first that the report is heading "Top 5 TIMED events"
> not "Top 5 WAIT events".
>
> Now consider this - if you have used 4 CPU seconds
> in 1 elapsed second, what percentage of your CPU
> have you used ? It depends on the number of CPUs
>
> If you have waited for Disk I/O for 20 seconds in one
> elapsed second, how long (on average) has each
> user waited ? It depends on the number of concurrent
> users requesting disk I/O in that period.
>
> It was (in some ways) a big mistake for Oracle to put
> the CPU usage exactly where they did; although it is
> a very important number to have available when you
> are looking at the wait events.
>
> Ignore the CPU percentage from statspack. Factor
> in the number of CPUs, the number of concurrent
> active users, the elapsed time of the report. And even
> then you haven't shown any reason why you might
> need to change anything.
>
> Regards
>
> Jonathan Lewis
>
> http://www.jlcomp.demon.co.uk/faq/ind_faq.html
> The Co-operative Oracle Users' FAQ
>
> http://www.jlcomp.demon.co.uk/seminar.html
> Public Appearances - schedule updated Dec 23rd 2004
>
>
> ----- Original Message -----
> From: "Jaffar_DBA" <sjaffarhussain_at_gmail.com>
> To: "Active DBA" <oracle-l_at_freelists.org>
> Sent: Sunday, January 09, 2005 1:48 PM
> Subject: CPU Time
>
> Hello list,
>
> If I have CPU time as my top most wait, what should I look for reducing it?
> Below are my top fives events and almost always, the top wait event is
> CPU Time .
>
> Top 5 Timed Events
> ~~~~~~~~~~~~~~~~~~ %
> Total
> Event Waits Time (s) Ela
> Time
> -------------------------------------------- ------------ ----------- --------
> CPU time
> 4,625 91.49
> db file sequential read 95,317 140
> 2.76
> log file sync 47,051
> 118 2.33
> log file parallel write 55,772
> 79 1.56
> SQL*Net more data to client 46,977 69 1.36
>
> Application background:
>
> My application is an oline share trading application. We have only 3
> hours in the morning and 3 hours in the evening trading session.
>
> --
> Best Regards,
> Jaffar, OCP DBA
> Banque Saudi Fransi
> Saudi Arabia
> --
> http://www.freelists.org/webpage/oracle-l
>
> --
> http://www.freelists.org/webpage/oracle-l
>

-- 
Best Regards,
Jaffar, OCP DBA
Banque Saudi Fransi
Saudi Arabia
--
http://www.freelists.org/webpage/oracle-l