Re: tkprof elapsed time clarification

From: <dbaoracleind_at_yahoo.com>
Date: 13 Jul 2006 09:42:49 -0700
Message-ID: <1152808969.505535.205320@35g2000cwc.googlegroups.com>

Thanks for the information. I will dig a little deeper into it.

Sam

Charles Hooper wrote:
> dbaoracleind_at_yahoo.com wrote:
> > Hi
> >
> > I have a trace report created from tkprof that shows the following inf
> > for a query run.
> >
> > call count cpu elapsed disk query current
> > rows
> > ------- ------ -------- ---------- ---------- ---------- ----------
> > ----------
> > Parse 1 0.02 0.06 0 8 0
> > 0
> > Execute 1 0.01 0.02 0 0 0
> > 0
> > Fetch 9249 2.40 725.79 0 0 0
> > 138720
> > ------- ------ -------- ---------- ---------- ---------- ----------
> > ----------
> > total 9251 2.43 725.88 0 8 0
> > 138720
> >
> >
> > I am really interested in the elapsed time which shows as 725 seconds.
> > I also had a select sysdate from dual before and after this query that
> > showed the time taken for the query to complete as 12 secs instead of
> > 725 secs.
> >
> > I am obviously missing something and would like to know where it is.
> >
> > Appreciate your help in advance,
> >
> > Thanks
> >
> > Sam

>

> Quoting from "Optimizing Oracle Performance" by Cary Millsap pg 84:
> "Oracle's tkprof utility produces erroneous results in more cases than
> you might have imagined, especially in the STAT line processing.
> Oracle's tkprof has an exceptional reputation for reliability, but I'm
> convinced that one reason the tool maintains this reputation is that
> people simply never bother to double-check its output. To confirm or
> refute whether tkprof is giving correct output is impossible to do
> without studying raw trace data."

>

> You found a problem - it may be a bug in Oracle, a bug in tkprof, a bug
> in the time reported by the operating system, a time synchronization
> utility that just happened to fire when the trace file was created,
> possibly using tkprof for Oracle 8 to analyze an Oracle 9 trace file,
> or something else. Consider taking a look at the raw trace file.

>

> Charles Hooper
> PC Support Specialist
> K&M Machine-Fabricating, Inc.
Received on Thu Jul 13 2006 - 11:42:49 CDT