Last updated on JANUARY 07, 2015
Applies to:Oracle Database - Enterprise Edition - Version 220.127.116.11 and later
Information in this document applies to any platform.
- Query is slower on 11g than 10g and chooses a different plan
- Select contains a query block that references a column that is a Virtual column or has a function based index (which is implemented with a virtual column) upon it but the column is not referenced directly. For example: If there is a table T1 with a column COL1 in the where clause which has a function based index on it : UPPER(COL1), then the following select would have potential to exhibit the problem :
- Predicate is such that Dynamic Sampling is required to generate accurate statistics
- Setting Dynamic Sampling does not help
- Setting optimizer_features_enable to 10.2.0.3 query performance is restored
Upgrade from 10gR2 to 11gR2.
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