How to use the _FIX_CONTROL hidden parameter

(Doc ID 827984.1)

Last updated on JANUARY 12, 2018

Applies to:

Oracle Database - Enterprise Edition - Version to [Release 10.2 to 11.2]
Information in this document applies to any platform.
***Checked for relevance on 01-May-2012***


_FIX_CONTROL is a special hidden dynamic parameter introduced in which can be used to enable or disable certain bug fixes. This is typically used in the optimizer area to allow specific fixes to be turned on or off as some fixes can have a significant  effect on execution plans.


You are using the parameter _FIX_CONTROL to  enable or disable specific patches. 

When you try to add the parameter you get:

SQL> ALTER SESSION SET "_FIX_CONTROL"='6626018:ON','6660162:ON','6440977:ON';
ALTER SESSION SET "_FIX_CONTROL"='6626018:ON','6660162:ON','6440977:ON'
ERROR at line 1:
ORA-02248: invalid option for ALTER SESSION


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