Re: Find out how many CPUs ?

From: joel garry <joel-garry_at_home.com>
Date: 29 Sep 2006 14:35:07 -0700
Message-ID: <1159565707.782436.221620@e3g2000cwe.googlegroups.com>

fitzjarrell_at_cox.net wrote:
> Comments embedded.
> Charles Hooper wrote:
> > Sybrand Bakker wrote:
> > > On 29 Sep 2006 10:41:49 -0700, "Charles Hooper"
> > > <hooperc2000_at_yahoo.com> wrote:
> > >
> > > >My memory is a bit fuzzy. Isn't there
> > > >another layer of views that the database needs to drill through to
> > > >reach the data when accessing through V$OSSTAT, rather than GV$OSSTAT?
> > >
> > >
> > > Apart from that this is a 10g specific answer.
> > > 9i and 8i customers need to check the init.ora parameter cpu_count.
> > >
> > > --
> > > Sybrand Bakker, Senior Oracle DBA
> >
> > Thanks for the additional input. So, in 9i and 8i Oracle believes the
> > DBA, while in 10g Oracle believes the OS?

> No. Oracle still retrieves this information from the O/S, however in
> 10g it retrieves more of it as the CPUs are more complex than they were
> at the time 8i and 9i were written. The DBA should never set the
> CPU_COUNT in the init.ora parameters, and the associated documentation
> states this.

>


> > Would it be possible to

> > determine the number of CPUs in an 8i or 9i database based on some of

> > the other statistics recorded in the database?  For example: 2 CPUs = 2

> > CPU seconds for every 1 clock second, 4 CPUs = 4 CPU seconds for every
> > 1 clock second.

> That isn't necessary as Oracle does query the O/S for the cpu count,
> even in 8i.

>


> >

> > 10g: Would it be more efficient, although more difficult to read, to

> > select directly from SYS.X$KSUCPUSTAT?  This would eliminate a couple

> > synonym look ups, view definition look ups, and a UNION:

> > SELECT

> >   MAX(DECODE(KSUCPUSTATNAME,'NUM_CPUS',KSUCPUSTATVALUE,1)) CPUS,

> >   MAX(DECODE(KSUCPUSTATNAME,'NUM_CPU_CORES',KSUCPUSTATVALUE,1))

> > CPU_CORES,

> >   MAX(DECODE(KSUCPUSTATNAME,'BUSY_TIME',KSUCPUSTATVALUE,0)) BUSY_TIME,

> >   MAX(DECODE(KSUCPUSTATNAME,'IDLE_TIME',KSUCPUSTATVALUE,0)) IDLE_TIME,

> >

> > (MAX(DECODE(KSUCPUSTATNAME,'BUSY_TIME',KSUCPUSTATVALUE,0))/MAX(DECODE(KSUCPUSTATNAME,'NUM_CPUS',KSUCPUSTATVALUE,1)))/24/

> > 3600/100 BUSY_DAYS,

> >

> > (MAX(DECODE(KSUCPUSTATNAME,'IDLE_TIME',KSUCPUSTATVALUE,0))/MAX(DECODE(KSUCPUSTATNAME,'NUM_CPUS',KSUCPUSTATVALUE,1)))/24/

> > 3600/100 IDLE_DAYS

> > FROM

> > SYS.X$KSUCPUSTAT;
> >

> I believe Oracle would prefer you use the views supplied for that
> purpose.

>

For a good time, search "CPU_COUNT WRONG" on the bug database.

--
@home.com is bogus.
"Dear Jack: I am so glad you warned me about contacting heads of
state as I was just about to write to Castro." - Rose Kennedy
(November, 1962)

Received on Fri Sep 29 2006 - 16:35:07 CDT