Re: Rule-based vs cost-based optimization

I guess I should have mentioned, we analyze our databases weekly.

"Jim Kennedy" <kennedy-family_at_home.com> wrote in message news:1INF6.59272$xN4.4351607_at_news1.sttls1.wa.home.com...
> You need to analyze the tables or the CBO is not very effective. Get
> Lewis's new book.
> Jim
>
> "Chris" <me_at_nospam.com> wrote in message
> news:WbKF6.14214$q51.148808_at_news1.gvcl1.bc.home.com...
> > Hope everyone can stand one more question on rule-based vs. cost-based
> > optimization.
> >
> > I know that Oracle recommends that new applications be developed with
 CBO
> > and that Oracle has said that at some point RBO will no longer be
 supported.
> > I also know that some advanced features in 8i won't work with RBO. Can
> > anyone tell me if RBO is still supported in 9i?
> >
> > We have had CBO as a default for years but I am finding that developers
 have
> > been using the RULE hint here and there throughout various applications.
> > They tell me that they just couldn't get decent performance using CBO.
 Does
> > anyone know whether there are certain types of queries that give CBO
 trouble
> > and what (in general) the characteristics of those queries are?
> >
> > If anyone can help, TIA!!
> > --
> > Chris
> >
> >
> >
> >
>
>
Received on Thu Apr 26 2001 - 06:57:26 CEST