Re: RBO to CBO

From: DA Morgan <damorgan_at_x.washington.edu>
Date: Thu, 30 Dec 2004 10:10:21 -0800
Message-ID: <41d44380$1_1@127.0.0.1>

Niall Litchfield wrote:

> "DA Morgan" <damorgan_at_x.washington.edu> wrote in message
> news:41d3a2b3$1_2_at_127.0.0.1...
>

>>Oradba Linux wrote:
>>
>>
>>>Any major/minor issues to watch out for during the conversion especially
>>>with regards to sql written specifically to RBO
>>
>>Strip out hints and retune each statement as required.

>
>
> I wouldn't regard sql with hints as 'written especially for the CBO', since
> with the exception of the rule hint they would run under the CBO.

Earlier this year I did a one-month gig with a local telecom. Moved them from 8i RULE to 10g CBO. You'd likely be amazed how much of their SQL was hinted ... heavily hinted: And the CBO didn't like any of it.

-- 
Daniel A. Morgan
University of Washington
damorgan_at_x.washington.edu
(replace 'x' with 'u' to respond)

Received on Thu Dec 30 2004 - 12:10:21 CST