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

Last updated on APRIL 06, 2015

Applies to:

Oracle Database - Enterprise Edition - Version 10.2.0.1 to 11.1.0.7 [Release 10.2 to 11.1]
Information in this document applies to any platform.
**Checked for Relevance 26-Aug-2014**
Oracle Server Enterprise Edition - Version: 11.1.0.7
Performance
11.1.0.x
Child Cursors
Library Cache: Mutex X
kksfbc child completion
NLS_LENGTH_SEMANTICS
cursor: pin S wait on X


Symptoms

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

 

Changes

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

Cause

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