Re: Rule-based vs cost-based optimization
Date: Thu, 26 Apr 2001 04:43:41 GMT
Message-ID: <1INF6.59272$xN4.4351607_at_news1.sttls1.wa.home.com>
You need to analyze the tables or the CBO is not very effective. Get
Lewis's new book.
"Chris" <me_at_nospam.com> wrote in message
news:WbKF6.14214$q51.148808_at_news1.gvcl1.bc.home.com...
Jim
> Hope everyone can stand one more question on rule-based vs. cost-based
>
> I know that Oracle recommends that new applications be developed with CBO
> and that Oracle has said that at some point RBO will no longer be
supported.
> I also know that some advanced features in 8i won't work with RBO. Can
> anyone tell me if RBO is still supported in 9i?
>
> We have had CBO as a default for years but I am finding that developers
have
> been using the RULE hint here and there throughout various applications.
> They tell me that they just couldn't get decent performance using CBO.
Does
> anyone know whether there are certain types of queries that give CBO
trouble
> and what (in general) the characteristics of those queries are?
>
> If anyone can help, TIA!!
> --
> Chris
>
>
>
>
Received on Thu Apr 26 2001 - 06:43:41 CEST