FreeLists / oracle-l / Re: hinting and the rule based optimizer

[Juriy.Matey@xxxxxxx]

Ryan,
the ONLY hint you can use with RBO is /*+ rule */
Any other hint will force using CBO.

Juriy Matey





<ryan.gaffuri@xxxxxxx>
Sent by: oracle-l-bounce@xxxxxxxxxxxxx
04/01/2004 03:03 PM
Please respond to oracle-l

 
        To:     oracle-l@xxxxxxxxxxxxx
        cc: 
        Subject:        hinting and the rule based optimizer


We have a legacy 8.1.7.3 instance that is in RBO mode. My group does not 
own it, so we cannot change it to CBO.

When I hint anything from an index to ordered, etc... it switches to the 
CBO and since nothing is analyzed, it's an even worse plan... Not allowed 
to analyze the tables either because it's not our property.

Any rules around hinting the RBO in 8.1.7.3? Why would it switch to the 
CBO from a simple hint? I never use the RBO so please bare with me. 

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