Re: How to trace the oracle optimizer...

Daniel Roy wrote:
>
> I should add that event 10053 works only with CBO. If you use RBO
> (i.e. optimizer_mode = "rule", or "choose" with the tables not having
> statistics), event 10053 doesn't work.
>
> Daniel
>
> > do you mean that you want to see what decisions the optimiser took when
> > creating an execution plan ?
> > If so, you want to be using event 10053 which will create a trace file
> > with details.
> >
> > HTH
> >
> > Regards,
> > Norman.
> >

true, but there is not much to trace with rule - it just the follows the sequence of rules listed in the performance guide.

hth
connor

-- 
=========================
Connor McDonald
http://www.oracledba.co.uk

"Some days you're the pigeon, some days you're the statue"