Re: Account DB CPU vs OS CPU
Date: Mon, 28 Sep 2009 10:25:35 +0200
I have do some data reasearch this weekend.
So I got these figures:
Total CPU time available for 1 hour (number of cpu * 3600): 72000 seconds
Host CPU Utilization (from dba_hist_sysmetric_summary) for 1 hour average:
Database CPU (DB CPU + RMAN cpu + background cpu time from DBA_HIST_SYS_TIME_MODEL) for 1 hour: 53419 seconds which is around 74.19% CPU usage when databases are idle (got this figure from other idle RAC nodes): 18%
So 74.19 + 18 we get 92.19%, quite close to 97.59%. Looks pretty good how Oracle count CPU.
-- LSC On Fri, Sep 25, 2009 at 5:51 AM, Tanel Poder <tanel_at_poderc.com> wrote::Received on Mon Sep 28 2009 - 03:25:35 CDT
> The background processes CPU time is accounted separately from DB CPU ->
> its called "background cpu time"
> On Fri, Sep 25, 2009 at 2:34 AM, Christo Kutrovsky <
> kutrovsky.oracle_at_gmail.com> wrote:
>> How did you measure CPU usage over the period of time ?
>> I can't tell you for sure, but here's a few thinking points.
>> - dbwriter and other background processes - are these accounted in DB CPU
>> - LMS processes - are these accounted in DB CPU ?
>> - listener, clusterware, process initialization - those are not accounted
>> Christo Kutrovsky
>> Senior Consultant
>> The Pythian Group