Re: statistics_level='ALL' with 10046, level 8 : Cost/Benefit Analysis

One thing to definetely be aware of is the timed_os_statistics, that you implicity set to 5 per default if setting timed_statistics to ALL. See

http://download.oracle.com/docs/cd/B19306_01/server.102/b14237/initparams215.htm#CHDCDEIC

Cheers

Stefan

On Tue, Sep 23, 2008 at 6:16 PM, Hemant K Chitale <hkchital_at_singnet.com.sg> wrote:
>
> I have a vendor that insists on running a batch job with
> statistics_level='ALL' and event 10046, level 8 ,both set at the session
> level in *production* only to diagnose performance issues. Furthermore, it
> would seem that the vendor will rely on AWR reports and tkprof's of the
> 10046 trace files sent to him post-facto (note : not the trace file, but
> the tkprof of it).
>
> I have run a few tests with my own dummy tables and SQLs to show the impact
> of 'ALL' and level 8 to the job execution time.
>
> I have proposed a Cost/Benefit analysis -- the "Cost" is the increase in job
> runtime (for a batch job that can take 8-12 hours normally) and the
> "Benefit" being the additional performance diagnostics that is done from the
> tkprof's and/or AWRs.
>
> Do we have a documented / evidenced list of benefits in tkprof when
> statistics_level is set to 'ALL' ?
> What additional information can I see in an AWR report (generated after the
> fact) ?
>
>
>
> Hemant K Chitale
>
> http://hemantoracledba.blogspot.com
>
>
>
> --
> http://www.freelists.org/webpage/oracle-l
>
>
>

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Stefan P Knecht
Senior Consultant
Infrastructure Managed Services

Trivadis AG
Europa-Strasse 5
CH-8152 Glattbrugg

Phone +41-44-808 70 20
Fax +41-808 70 12
Mobile +41-79-571 36 27
stefan.knecht_at_trivadis.com
http://www.trivadis.com

OCP 9i/10g SCSA SCNA
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