RE: Rule Based Optimizer

From: Jamadagni, Rajendra <Rajendra.Jamadagni_at_espn.com>
Date: Wed, 11 Jun 2003 09:43:27 -0700
Message-ID: <F001.005AF40F.20030611092101@fatcity.com>

Tom,

I thought the rules of precedence were for RBO (the R in RBO). Whereas CBO was _intelligent_ enough to choose a path based on information available on hand.

Raj

---

Rajendra dot Jamadagni at nospamespn dot com All Views expressed in this email are strictly personal. QOTD: Any clod can have facts, having an opinion is an art !

-----Original Message-----

Mercadante, Thomas F
Sent: Wednesday, June 11, 2003 9:30 AM
To: Multiple recipients of list ORACLE-L

CBO was what I learned on in late version of 5.x and 6.0.  It was what Oracle taught developers back then - with the chart showing the precedence of how indexes were selected for a spcific query.  And how the order of the tables in the FROM clause was *very* important in telling the CBO how to operate.  Of course, that was when the developers had to know everything about the data within all the tables to get things to work right.

Tom Mercadante
Oracle Certified Professional

********************************************************************This e-mail 

message is confidential, intended only for the named recipient(s) above and may contain information that is privileged, attorney work product or exempt from disclosure under applicable law. If you have received this message in error, or are not the named recipient(s), please immediately notify corporate MIS at (860) 766-2000 and delete this e-mail message from your computer, Thank

you.*********************************************************************2

Received on Wed Jun 11 2003 - 11:43:27 CDT