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Optimizer point of view on literal values usage

Posted by Игорь Усольцев on August 5, 2011

Limitations of the Oracle Cost Based Optimizer [ID 212809.1]:

“From the optimizer point of view, it is recommended to use literal values where there is the possibility of significant performance differences associated with using different bind variable values and applying the same plan for all executions. In these cases the choice of a good plan usually significantly outweighs the potential usage of shared pool space (assuming that the shared pool usage is not excessive)”

It seems interesting for me! This quote from MOS doc is not ancient – last update 25-JUL-2011. Bind peeking ( from 9i), and Adaptive Cursor Sharing (11g) technologies work for a long time already, but the literal values usage are still preferable for CBO %)


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