Re: Is SQL procedural or non-procedural?

From: Paul <>
Date: Tue, 13 Jun 2006 20:32:55 +0100
Message-ID: <>

"David Cressey" <> wrote:

> I'm familiar with the optimizer that was built into DEC Rdb/VMS. It had
> the effect that I described in my earlier post.

I'm talking about the Oracle one. Rdb/VMS - isn't that related to Interbase precursors?  

> People who are familiar with DB2 assure me that the DB2 optimizer was also
> very good.
> I've seen Oracle shops converting from RBO to CBO, and they need to go
> through a cultural shift.
> What does "CBO, the fundamentals" teach?

Your quote

"and the "programmers could focus on what data they wanted, instead of how to access it."

With the CBO, you can't do that - there are loads of parameters to fiddle with. That's what it tries to teach - how to best tune those parametres for your system.

As for RBO vs. CBO, there were "tricks" that you could use with the RBO which no longer work with the CBO - hence the learning curve.



plinehan __at__ yahoo __dot__ __com__

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Oracle, (Enterprise Ed.)

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Received on Tue Jun 13 2006 - 21:32:55 CEST

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