Re: EXPLAIN PLAN : better with RULE!

"When no stats" it uses RBO.

Without stats the CBO cannot work effectively.

and STOP supposing !

the index could be bigger than the table.

Try with 100% stats on everything( do not forget system stats or indexes ) . Then we will look at the plan generated by CBO

ALL and FIRST row hints should then be the major modifiers.

"Epicentre Team B Annecy" <carmanet_at_epicentre.fr> wrote in message news:ah0qqj$9oq$1_at_wanadoo.fr...
> I know the influence of statistics for CBO,
> and I know that when no stats, CBO makes join from left to right
> in the FROM clause,
> but is CBO not supposed, when no stats, knowing at least that indexes
exist
> on tables?
>
> Thanks again.
>
> "Loadrunner" <load_at_runner.com> a écrit dans le message news:
> 1026810930.9839.0.nnrp-10.c2d92da9_at_news.demon.co.uk...
> > Can you confirm that you have analyzed tables with the "For Table For
All
> > Columns For All Indexes" clause?
> >
> > If very large table estimate the statistics.
> >
> > The explain plan produced when CBO active can vary dramatically with or
> > without statistics.
> >
> >
>
>
Received on Tue Jul 16 2002 - 06:04:37 CDT