Re: RBO to CBO

"DA Morgan" <damorgan_at_x.washington.edu> wrote in message news:41d44380$1_1_at_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)

Hi Daniel

Was it 10g without any patches?
There are some issues in CBO (9i/9iR2) f.ex with complex views. Does CBO work better in 10g than 9iR2 .

Do you have experience with Heterogenous Services and External tables, what should be watch out (in CBO)?

Jack Received on Fri Dec 31 2004 - 02:28:09 CST