IBM Support

IC68268: PERFORMANCE ENHANCEMENT TO MEMORY ALLOCATION CODE FOR CONCURRENT INSERT/UPDATE WITH CODE PAGE CONVERSION

Subscribe

You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • It was determined that during heavy concurrent insert/update
    operations involving code page conversion into a unicode
    database that the malloc'ing of memory from the OS can become a
    bottleneck during the code page conversion process.
    
    environment:
    
    1. DB2 9.5 and up
    2. The database codepage is UTF.
    3. The application codepage is not.
    4. There are frequent and concurrent insert/update to the
    database.
    
    this was uncovered during a customer PMR with 50-100 concurrent
    import jobs against the same table.  After a certain point the
    percentage of time spent in ossLockGetConflict() reaches 75%
    trying to malloc and free memory.
    

Local fix

Problem summary

  • Users Affected: Any doing heavy concurrent insert/update
    
    operations with code page conversion.
    Problem Description: During a heavy concurrent insert / update
    with code page conversion, perfomance can be affected by memory
    operations
    Problem Summary: see above.
    

Problem conclusion

  • Problem was first fixed in Version 9.7 FixPak 3
    

Temporary fix

Comments

APAR Information

  • APAR number

    IC68268

  • Reported component name

    DB2 FOR LUW

  • Reported component ID

    DB2FORLUW

  • Reported release

    970

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2010-04-28

  • Closed date

    2010-10-07

  • Last modified date

    2010-10-07

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

    IC67989

  • 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

  • R970 PSN

       UP



Document information

More support for: DB2 for Linux, UNIX and Windows

Software version: 9.7

Reference #: IC68268

Modified date: 07 October 2010