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RE: *Measuring sql performance (elapsed time and scalability) by number of logical reads

From: Cary Millsap <cary.millsap_at_hotsos.com>
Date: Wed, 3 May 2006 10:56:30 -0500
Message-ID: <C970F08BBE1E164AA8063E01502A71CF518B13@WIN02.hotsos.com>


I very rarely see the intrusion change the fundamental nature of the problem. ...In my experience, you most often end up with an appropriate diagnosis in return for some small number of times that you cause the performance intrusion.

10200 is especially intrusive, because it emits a line of text to the trace file for every buffer cache access that takes place.

Cary Millsap
Hotsos Enterprises, Ltd.
http://www.hotsos.com
Nullius in verba  

Hotsos Symposium 2007 / March 4-8 / Dallas Visit www.hotsos.com for curriculum and schedule details...

-----Original Message-----
From: bill thater [mailto:shrekdba_at_gmail.com] Sent: Wednesday, May 03, 2006 10:20 AM
To: Cary Millsap
Cc: Dimitar Radoulov; oracle-l_at_freelists.org Subject: Re: *Measuring sql performance (elapsed time and scalability) by number of logical reads

On 5/3/06, Cary Millsap <cary.millsap_at_hotsos.com> wrote:
> I agree. And that's what we get on the PARSE, EXEC, FETCH, UNMAP, SORT
> UNMAP, and STAT lines. It's not presented in a lot of detail, but it's
a
> tradeoff between detail and measurement intrusion.
>
> There's certainly more detail available; for example, events 10104,
> 10200, etc., but the measurement intrusion is significantly greater
for
> some of those events than it is for 10046.

is it great enough to skew the results?

--
--
Bill "Shrek" Thater     ORACLE DBA
       shrekdba_at_gmail.com
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Received on Wed May 03 2006 - 10:56:30 CDT

Original text of this message

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