ANSI SQL Statement Running Slow in 12C
(Doc ID 2255117.1)
Last updated on AUGUST 04, 2018
Applies to:Oracle Database - Standard Edition - Version 184.108.40.206 and later
Information in this document applies to any platform.
- After upgrading the database from 220.127.116.11 to 18.104.22.168, the ANSI version of SQL statements take long time to complete
- The non-ANSI version of the same SQL statements take only less than a second to complete with following plans:
- Setting OPTIMIZER_FEATURES_ENABLE = '22.214.171.124' resolves the issue with performance for the ANSI query.
- Setting _OPTIMIZER_UNNEST_SCALAR_SQ to FALSE also gives good plan but push predicate does not happen.
Database upgrade from 11.2 to 12.1.
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