PK61785: INCORRECT AVGROWLEN PASSED TO DFSORT ON REORG WITH PARTITION RANGE AFTER ALTER ADDED COLUMN

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• A table in a partitioned table space with compression enabled
  is modified and new columns are added. If a REORG TABLESPACE
  with option KEEPDICTIONARY and a partition range is executed
  then the AVGROWLEN parameter passed to DFSORT may contain a
  value which is too small for the records being sorted.
  

Local fix

• When alter added columns are detected during the REORG the
  AVGROWLEN parameter will be set to the maximum record length
  as all rows have to be expanded to uncompressed external format.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All DB2 9 for z/OS utility users of REORG    *
  *                 TABLESPACE                                   *
  ****************************************************************
  * PROBLEM DESCRIPTION: The average row length being passed to  *
  *                      DFSORT may not take into account that   *
  *                      compressed data needs to be             *
  *                      decompressed or that ALTER added        *
  *                      columns have to be manifested during    *
  *                      the UNLOAD phase of REORG TABLESPACE    *
  *                      with partition parallelism. This can    *
  *                      result in the average row length value  *
  *                      being too low for the actual data that  *
  *                      is sorted and may result in DFSORT      *
  *                      termination with message MSGICE046A     *
  *                      SORT CAPACITY EXCEEDED and REORG        *
  *                      ABEND04E RC00E40005.                    *
  ****************************************************************
  * RECOMMENDATION: Apply corrective PTF when available          *
  ****************************************************************
  When running REORG TABLESPACE with partition level parallelism
  the average row length for each partition may be calculated
  incorrectly when either ALTER added columns need to be
  manifested or when records have to be uncompressed to build
  a new compression dictionary. Since the average row length
  is used to calculate sort work data set sizes this can lead
  to shortages if the value is too low.
  
  When partition parallelism is selected by REORG message
  MSGDSNU1160I PARTITIONS WILL BE UNLOADED/RELOADED IN PARALLEL,
  NUMBER OF TASKS=n will be issued. The average row length is
  already calculated correctly for single unload tasks.
  

Problem conclusion

• Average row length on the partition level during REORG
  TABLESPACE will take ALTER added columns and decompression of
  rows into account.
  

Temporary fix

Comments

APAR Information

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

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

  UK35830

Modules/Macros

• DSNURFIT
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• R910 PSY UK35830

     UP08/05/10 P F805

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.