Re: Optimizer change from 8i-9i

From: Wolfgang Breitling <breitliw_at_centrexcc.com>
Date: Wed, 11 May 2005 06:58:24 -0600
Message-ID: <42820170.1090507@centrexcc.com>

Christian,

while I agree with you that setting optimizer_features_enable to a back release is not the same as running the optimizer at that release level, this is actually not a good example in this context as complex_view_merging is set to false by optimizer_features_enable=8.1.7

Christian Antognini wrote:
> Hi=20
>
>

>> About the RBO change in 9i, can you show me a test case?

>
>
> E.g. complex_view_merging could lead to different execution plans.
> If I run the following statements in 8.1.7 and 9.2.0 I get different =
> results...
> (notice that both database have a "minimal" INIT.ORA that doesn't modify =
> any optimizer parameter)
>

-- 
Regards

Wolfgang Breitling
Centrex Consulting Corporation
www.centrexcc.com
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Received on Wed May 11 2005 - 09:02:59 CDT