Re: When was the RBO deprecated?

On Wed, 22 Jun 2005 19:42:34 +0200, "Gerard H. Pille" <ghp_at_skynet.be> wrote:

>Jim Smith wrote:
>> I know CBO was introduced in Oracle 7 (7.1?), but when did oracle first
>> say "stop using RBO because it is going away?"
>They said to stop using the RBO the minute they released the CBO, even when
>queries with CBO produced different results from those with RBO. Guess which
>were correct.
>

The RBO execution plans basically are only correct when you still subscribe to the old myth 'full table scans are bad'

>Even with 9.2.0.6, RBO beats CBO fingers in the nose,
Not my experience. You probably never modified the optimizer* init.ora parameters. They shouldn't be left on their defaults!

not forgetting all the
>effort one has to put into keeping statistics valid, something Oracle could have
>done automatically,

You can gather the statistics for a schema with one dbms_stats call, and you can submit that command through dbms_job. Objection waived.

 but were afraid of because of performance (benchmarks?). As
>if their analyze doesn't need resources.
>
>Gerard

You can analyze only stale tables.

Time to learn CBO, I guess, or stick to 9i forever and become a dinosaur.

--
Sybrand Bakker, Senior Oracle DBA