Re: RBO to CBO

From: Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk>
Date: Fri, 31 Dec 2004 11:41:53 +0000 (UTC)
Message-ID: <cr3du1$ojk$1@titan.btinternet.com>

One of the important differences between 9i and 10g is the number of optimizer options in 10g that are costed. So your complex view merging issue may be resolved.

9i simply does it if possible
10g calculates costs with and without merging and chooses the cheaper option.

Regards

Jonathan Lewis

http://www.jlcomp.demon.co.uk/faq/ind_faq.html The Co-operative Oracle Users' FAQ

http://www.jlcomp.demon.co.uk/seminar.html Public Appearances - schedule updated Dec 23rd 2004

"Jack" <none_at_mail.com> wrote in message news:t48Bd.86$iB.66_at_read3.inet.fi...
>
> Was it 10g without any patches?
> There are some issues in CBO (9i/9iR2) f.ex with complex views.
> Does CBO work better in 10g than 9iR2 .
>
> Do you have experience with Heterogenous Services and External tables,
> what should be watch out (in CBO)?
>
> Jack
>
Received on Fri Dec 31 2004 - 05:41:53 CST