Re: Top 5 Timed Events - % Total Call Time does not add upto to 100%

From: Jared Still <>
Date: Mon, 22 Nov 2010 09:08:46 -0800
Message-ID: <>

On Mon, Nov 22, 2010 at 1:35 AM, Oracle Dba Wannabe <> wrote:

> c) The table only shows the top 5 - so it would not necessarily have to add
> up to 100 - it would just show the dominant events and there overall impact
> - most likely the missing remaining percentage (40% in this case) is of no
> consqeuence to performance

You have probably heard Ahmdahl's Law mentioned from time to time on this list.

Though it is often used in connection with calculating the expected improvements
made by parallelization, it also applies to determining what processes to consider
for system improvements.

Hence the top 5 list. These are where the most time is being spent.

If a process (not likely in the top 5) is consuming 1% of a given resource, the most improvement you can hope to make by optimizing the use of that resource is 1%. A full 1% improvement can only be made by eliminating the use of that resource.

Better to concentrate on where the most time is being spent - the Top N (5 in this case)

Jared Still
Certifiable Oracle DBA and Part Time Perl Evangelist Oracle Blog: Home Page:

Received on Mon Nov 22 2010 - 11:08:46 CST

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