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" Library Cache: Mutex X " On Koka Cursors (LOBs) Non-Shared : (Doc ID 758674.1)

Last updated on FEBRUARY 20, 2019

Applies to:

Oracle Database Cloud Schema Service - Version N/A and later
Oracle Database Exadata Cloud Machine - Version N/A and later
Oracle Cloud Infrastructure - Database Service - Version N/A and later
Oracle Database Cloud Exadata Service - Version N/A and later
Oracle Database Backup Service - Version N/A and later
Information in this document applies to any platform.


In testing prior to going to 11g, you find that application procedures which had completed in Oracle 10g in  minutes (e.g. 30-40 ) are now taking 12 hours or more ... or may not complete at all

Symptom #1

Using Oracle 11g with Automatic Memory Management you may find within a short amount of time CPU Utilization reached up to 100% and detected unusual Wait Event stats for 2 or more of the following: 

Symptom #2

Exceptional time spent for one of the following

Symptom #6



Testing or usage after upgrading to 11.1.0.x from 10g or earlier

Using or switching to CHAR NLS_LENGTH_SEMANTICS vs. the default value of BYTE

Comment: NLS_LENGTH_SEMANTICS is set at the Column level for Tables, Views, Indexes, or Packages/Procedures for Sting based datatypes including [N]CHAR ; [N]VARCHAR2 ; [N]CLOB


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