Re: SQL Tuning
Date: Sat, 05 Jul 2003 18:39:06 +0200
Message-ID: <emvdgvoroisfkfcm5frgm6nab1tu56v5o9_at_4ax.com>
On Sat, 05 Jul 2003 15:04:14 GMT, - (-) wrote:
>I was just saying that making the CBO do what your want is very
>difficult. Sometimes the CBO seems to have a mind of it's own but not
>a very smart one. Also sometimes thing just become too compilate
>because you have to take too much factors into consideration to be
>cost effective. The quest for inteligent life in the CBO is one of
>those things I like to avoid because I think it would not be cost
>effective as it would take a lot of time.
>
The worst decision you can make is stick with the RBO.
Whether you want it or not you *must* learn the CBO.
Also in CBO the execution path is much less dependent on the actual
contents of the statement.
There are many documents available on how the CBO makes decisions.
Read them.
Sybrand Bakker, Senior Oracle DBA
To reply remove -verwijderdit from my e-mail address Received on Sat Jul 05 2003 - 18:39:06 CEST