If there're already hints like ordered and use_nl that tell Oracle how to join,
lack of statistics is less of a problem. In fact, you may need to use those two
hints in some queries against data dictionary even in pre-9i Oracle.
Yong Huang
- Tanel Poder <tanel.poder.003_at_mail.ee> wrote:
> Hi!
>
> Just for the record, in 9.2 some views such dba_extents use "ordered" and
> "use_nl" hints, which force usage of CBO.
> If you don't have statistics calculated nor optimizer_dynamic_sampling set
> to at least 2, then you'll be using CBO with default statistics, which
> usually are quite misleading.
>
> Tanel.
>
> ----- Original Message -----
> To: "Multiple recipients of list ORACLE-L" <ORACLE-L_at_fatcity.com>
> Sent: Tuesday, October 28, 2003 11:09 PM
>
>
> > The data dictionary should not have any statistics on them and thus will
> use
> > rule as a "rule" so to speak.
> >
> > If you have run stats on the data dictionary you coul dbe running into
> some
> > odd bugs.
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Author: Yong Huang
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Received on Tue Oct 28 2003 - 17:04:28 CST
