DA Morgan wrote:
> Noons wrote:
>
> > DA Morgan wrote:
> >
> >
> >>Well EXPLAIN PLAN certainly doesn't like it:
> >
> >
> > Funny how 10.1 is so different from 9ir2...
> > I wonder how much we can rely on the explain plan "cost"
> > to mean anything, after all it's just a convention rather
> > than an absolute number.
> >
> > The stats on the other hand tell us exactly what
> > is going on re consistent gets vs physical gets.
> > Or so they should, but that's not 100% certain either!
>
> What I've heard is that the biggest difference between the
> 9i CBO and the 10g CBO is that in 10g the optimizer takes
> into account CPU. That may well be true but doesn't seem
> to explain the result.
I suspect that your comment is missing 'by default' at the end of it!
CPU costing is certainly available in 9.2 You get it when you choose to
collect system statistics.
Niall Litchfield
Oracle DBA
http://www.niall.litchfield.dial.pipex.com
Received on Mon Jan 10 2005 - 11:04:37 CST
