Re: Oracle CBO question

From: Jared Still <jkstill_at_gmail.com>
Date: Thu, 7 Jun 2007 14:05:03 -0700
Message-ID: <bf46380706071405j66a30223wfee040f397aa2791@mail.gmail.com>

On 6/7/07, K Gopalakrishnan <kaygopal_at_gmail.com> wrote:
>
> Jared,
>
> N factorial permutations for N tables are theoretical limit. However
> in practice the number of combinations are optimized (read: limited)
> to a much smaller number than the thousands. If you start examining
> all the thousands of combinations the parse time itself will run for
> minutes and to avoid that there are limits defined for everywhere.

Yes, that was my point.

There is an 'optimizer_search_limit' and also
> '_new_initial_join_orders' limits the number of permutations .

Thanks.

-- 
Jared Still
Certifiable Oracle DBA and Part Time Perl Evangelist

--
http://www.freelists.org/webpage/oracle-l

Received on Thu Jun 07 2007 - 16:05:03 CDT