Re: Oracle AWR - Time Model Statistics / background elapsed time < background cpu time

From: Stefan Koehler <contact_at_soocs.de>
Date: Fri, 13 Mar 2015 13:32:48 +0100 (CET)
Message-ID: <130805328.207962.1426249968575.JavaMail.open-xchange_at_app01.ox.hosteurope.de>

Hi Phil,
that's true for the common used "Elapsed Time" vs. "DB CPU" as one RAC node got 160 CPUs, but the definition of the "Time Model Statistics" is different:

background elapsed time = Amount of elapsed time (in microseconds) consumed by database background processes background CPU time = Amount of CPU time (in microseconds) consumed by database background processes

The AWR report got an elapsed time of round about 3.600 seconds (59.96 mins). The "background elapsed time" (= 33,676 seconds) is defined differently as you can see.

However if the background elapsed time is the amount of elapsed time consumed by database background processes (and also top of the statistic tree), it must include the whole "background CPU time" in my opinion (and maybe more).

For example here it is in the right ball park: https://hoopercharles.wordpress.com/2010/01/13/working-with-oracle-time-model-data/

Thank you.

Best Regards
Stefan Koehler

Freelance Oracle performance consultant and researcher Homepage: http://www.soocs.de
Twitter: _at_OracleSK

> Phillip Jones <phil_at_phillip.im> hat am 13. März 2015 um 13:18 geschrieben:
>
> Hi,
> The CPU time is greater than the elapsed time because you have more than one CPU.
>
> Phil

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Received on Fri Mar 13 2015 - 13:32:48 CET