IBM Support

IT05940: POTENTIAL CORRUPTION DURING READAHEAD DATA PREFETCHING WHEN A DECIMAL KEY PART IS USED WITH INDEX COMPRESSION

A fix is available

DB2 Version 10.1 Fix Pack 6 for Linux, UNIX, and Windows

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APAR status

  • Closed as program error.

Error description

  • The symptoms that a customer would most likely see are incorrect
results from an index only scan, a keydata mismatch error from
an iscan fetch, a key not found during an update or delete
operation, or duplicates allowed to be inserted into the table.
The corruption that could cause these symptoms could occur
while doing read ahead prefetching of data pages from an index
scan and prefix compression is in affect for the index and index
has a decimal key part.

The corrupted byte will originally have a value of 0x00 and
incorrectly have be changed to 0x0C. The INSPECT command, when
run with the INDEXDATA option, will detect such corruption.

Local fix

  • Rebuild the corrupt index using the REORG INDEX(ES) command.

Problem summary

  • ****************************************************************
* USERS AFFECTED:                                              *
* Users of index compression                                   *
****************************************************************
* PROBLEM DESCRIPTION:                                         *
* See Error Description                                        *
****************************************************************
* RECOMMENDATION:                                              *
* Upgrade to DB2 version 10.1.0.5.                             *
****************************************************************

Problem conclusion

  • The problem is first fixed in DB2 version 10.1.0.5.

Temporary fix

  • 



Comments


    

  • 



APAR Information




    

  • APAR number
    IT05940
    • 

  • Reported component name
    DB2 FOR LUW
    • 

  • Reported component ID
    DB2FORLUW
    • 

  • Reported release
    A10
    • 

  • Status
    CLOSED  PER
    • 

  • PE
    NoPE
    • 

  • HIPER
    YesHIPER
    • 

  • Special Attention
    NoSpecatt
    • 

  • Submitted date
    2014-12-04
    • 

  • Closed date
    2015-07-10
    • 

  • Last modified date
    2015-07-10
    • 





    

  • APAR is sysrouted FROM one or more of the following:
    

    
IT05068
    

    • 

  • APAR is sysrouted TO one or more of the following:
    

    • 



Fix information


    

  • Fixed component name
    DB2 FOR LUW
    • 

  • Fixed component ID
    DB2FORLUW
    • 



Applicable component levels


    

  • RA10  PSN
       UP
    • 








      
              
                            

              

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Document Information


            

            


                        

            Modified date:
            

            10 July 2015
            

            
                      

        


        

        


      

    

  



    

  

  
    
            

          
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