IBM Support

IC92740: EXCESSIVE MEMORY USAGE IN DATABASE HEAP WHEN FAILING ALTER TABLE SPACE COMMANDS ARE ISSUED ACROSS A LARGE NUMBER OF TABLESPACES

Subscribe

You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • A 256K database heap allocation required for certain alter
    tablespace commands is unintentionally cached when no internal
    action is required.  The memory is cached per tablespace and
    will be reused for any subsequent alter tablespace command on
    the same tablespace (and may be freed as part of that
    operation).
    
    Commands known to miss freeing the buffer:
    
    1. ALTER TABLESPACE ... REDUCE  where the reduce operation
    cannot proceed.  This will be accompanied by a db2diag.log
    message:
    FUNCTION: DB2 UDB, buffer pool services, sqlbAlterPool, probe:15
    MESSAGE : ADM1534W  Table space "USERSPACE1" could not be
    reduced in size
              because there are used pages at the end of the table
    space.
    
    2. ALTER TABLESPACE ... REBALANCE where the rebalance operation
    is not required.
    
    The additional cached memory is rarely significant, reused per
    tablespace, and freed at database deactivation.  Systems with a
    very large number of tablespaces where the above commands are
    regularly issued may experience symptoms associated with
    abnormally high memory usage.
    

Local fix

  • avoid invalid ALTER TABLESPACE command where possible
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * all systems                                                  *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error Description                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Upgrade to DB2 version 9.7 Fix Pack 9                        *
    ****************************************************************
    

Problem conclusion

  • Problem first fixed in DB2 Version 9.7 Fix Pack 9
    

Temporary fix

Comments

APAR Information

  • APAR number

    IC92740

  • 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

    2013-06-03

  • Closed date

    2013-12-18

  • Last modified date

    2013-12-18

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

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

    IC95388

Modules/Macros

  • sqb
    

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 #: IC92740

Modified date: 18 December 2013