12.2 Cursor Mutex X Due To Sql Not Shared Because Of BIND_EQUIV_FAILURE

Bug 28794230  12.2 Cursor Mutex X Due To Sql Not Shared Because Of BIND_EQUIV_FAILURE

Symptoms:	Related To:
Leak (Resources Eg: File Handles) Mutex Contention Performance Affected (General)	Adaptive Cursor Sharing V$SQL_SHARED_CURSOR _optimizer_use_feedback _optimizer_adaptive_cursor_sharing _fix_control _optimizer_extended_cursor_sharing_rel

Description

Cursor leak with ACS(Adaptive Cursor Sharing) and CFB(Cardinality FeedBack) 
on short-running query and fix for Bug:23596611.
  
Rediscovery Notes
If a subsecond query with binds exhibits increasing child cursor count on
repeated executions on a release where the fix for Bug:23596611 exists and
disabling adaptive cursor sharing or statistics feedback prevents the cursor leak ,t
hen you may have encountered this bug.
 
You can see  BIND_EQUIV_FAILURE=Y in V$SQL_SHARED_CURSOR.
 
Workaround 

Several alternatives:
_optimizer_use_feedback=false
_optimizer_adaptive_cursor_sharing=false
_optimizer_extended_cursor_sharing_rel=none
_fix_control='23596611:OFF'  may also help in some cases

Alter system set _optimizer_use_feedback=false scope=spfile;

Alter system set _optimizer_adaptive_cursor_sharing=false scope=spfile;

Alter system set _optimizer_extended_cursor_sharing_rel=none scope=spfile;

Ref- 

(Doc ID 28794230.8)