Re: CPU_TIME > ELAPSED_TIME

yes, I also thought about this possibility before.

But this query is very simple, it's doing index unique scan on PK index. buffer gets per execution is only 3.

I can't image it run on multiple CPU at one time.

What do you think?

On 10/23/07, Niall Litchfield <niall.litchfield_at_gmail.com> wrote:
>
> Think of it like a gang of workmen working on a road. If it takes 8
> months for one man to complete the work it may take as little as 1
> month for 8 men to complete the same task - in the later case elapsed
> time is 1 month but work is 8 months. Cpu time works the same way.
>
> On 23/10/2007, Eagle Fan <eagle.f_at_gmail.com> wrote:
> > hi:
> >
> > The server has 8 physical CPU and each one has 2 threads. So CPU_COUNT
> is
> > 16.
> >
> > Could you explain more clearly? Do you mean cpu time overlap?
> >
> > Thanks
> >
> >
> > On 10/23/07, Niall Litchfield <niall.litchfield_at_gmail.com> wrote:
> > >
> > > how many cpu's do you have? each of them can do up to 1 second of work
> > > every second.
> > >
> > > On 10/23/07, Eagle Fan <eagle.f_at_gmail.com> wrote:
> > > >
> > > > Hi:
> > > >
> > > > I have had the same problem before. From v$sql:
> > > >
> > > > Delta CPU_TIME > Delta Elapsed_time. The sql is very simple, it's
> doing
> > > > "INDEX UNIQUE SCAN" using PK index.'
> > > >
> > > > How to explain this?
> > > >
> > > > Thanks
> > > >
> > > > SQL> select CPU_TIME,ELAPSED_TIME from v$sql where
> > > > hash_value=1769575534;
> > > >
> > > > CPU_TIME ELAPSED_TIME
> > > > ----------------------- -----------------------
> > > > 71025140000 70448619327
> > > >
> > > > SQL> exec dbms_lock.sleep(300);
> > > >
> > > > PL/SQL procedure successfully completed.
> > > >
> > > > SQL> select CPU_TIME,ELAPSED_TIME from v$sql where
> > > > hash_value=1769575534;
> > > >
> > > > CPU_TIME ELAPSED_TIME
> > > > ----------------------- -----------------------
> > > > 71030920000 70453943000
> > > >
> > > > SQL> select (71030920000-71025140000)/(70453943000-70448619327) from
> > > > dual;
> > > >
> > > > (71030920000-71025140000)/(70453943000-70448619327)
> > > > ---------------------------------------------------
> > > > 1.08571657
> > > >
> > > >
> > > >
> > > > --
> > > > Eagle Fan
> > > >
> > > > Oracle DBA
> > >
> > >
> > >
> > >
> > > --
> > > Niall Litchfield
> > > Oracle DBA
> > > http://www.orawin.info
> >
> >
> >
> >
> > --
> > Eagle Fan
> >
> > Oracle DBA
> >
>
>
> --
> Niall Litchfield
> Oracle DBA
> http://www.orawin.info
>

-- 
Eagle Fan

Oracle DBA

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