PH20972: AFTER FIX FOR PH16673, HANGING OR LOW PERFORM OR MEM OUTAGE WHEN UNLOADING FROM GLOBAL I/C OF A PARTITION TS --AI--

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• (HPU 5.1 only) After the fix for PH16673/PB58849 has been
  applied, the unload of the data from a unique image copy data
  set (COPYDDN) and requesting the unload for a partitioned table
  space (either described by the Db2 catalog or by the file
  provided for the DDLDDN option) faces some of the issues
  described below:
   - issue #1) the following message is issued :
   INZU223I PARALLELISM ACTIVATED FOR PARTITION PROCESSING.
   MAXIMUM DEGREE OF PARALLELISM IS LIMITED TO maxsort BY MAXSORT
  PARAMETER.
   while the unload is actually not processed with partition
  parallelism
  
   - issue #2) the performance is low: the CPU and elapsed time
  are unusually big
  
   - issue #3) the job fails with an out of memory issue
  
   - issue #4) if the input image copy contains the image copy of
  a non-partitioned table space and the unload specifies an ORDER
  clause, an ABENS0C4 occurs in function
  _inzzpiltBuilderAddFormating
  
   - issue #5) if the input image copy is the global image copy of
  a partition-by-growth tablespace and the output dataset (OUTDDN
  or UNLDDN option) is to be written on tape, the unload hangs.
  
   - issue #6) the unload hangs after the following message has
  been issued:
  INZU242I UNLOAD OF TABLESPACE dbname.tsname IS SPLIT which
  occurs if an ORDER clause is specified and a single output data
  set is requested (not a data set per partition) and the MAXPART
  limit (specified via the MAXPART option or the VUU060/ULMAXPAR
  parmlib parameter, if no MAXPART option) specifies a value less
  than the number of partitions from which the data is to be
  unloaded
  
  When a job is affected by this issue, more than one message
  INZX090 (up to one message per partitionned of the involved
  table space) is issued for the unload from the image copy
  

Local fix

• depending on the issue, the following workaround can be
  considered :
   - issue #1) none but this is only a display issue.
  
   - issues #2 and #3) if applicable, as the problem is less acute
  when the number of involved partitions is not bigger than a few
  tens, consider splitting up the unload into several unload
  statements involving less partitions.
  
   - issue #4) use the DDLDDN option to provide Db2 HPU with the
  description of a non-partitionned object, or, if the sequence of
  the unload rows is not mandatory, remove the ORDER clause
  
  - issue #5) if applicable, consider request the output data set
  be stored on disk.
  
  - issue #6) as the MAXPART limit is useless when a single output
  dat aset is requested, consider specifying MAXPART 0 .
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * Users of High Performance Unload                             *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * PH20972                                                      *
  * After the fix for PH16673/PB58849 has been applied, the      *
  * unload of the data from a unique image copy data set         *
  * (COPYDDN) and requesting the unload for a partitioned table  *
  * space (either described by te Db2 catalog or by the file     *
  * provided for the DDLDDN option) faces some of the issues     *
  * described below:                                             *
  *  - issue #1: the following message is issued:                *
  *  INZU223I PARALLELISM ACTIVATED FOR PARTITION PROCESSING.    *
  *  MAXIMUM DEGREE OF PARALLELISM IS LIMITED TO maxsort BY      *
  * MAXSORT PARAMETER.                                           *
  *  while the unload is actually not processed with partition   *
  * parallelism                                                  *
  *  - issue #2: the performance is low: the CPU and elapsed     *
  * time are unusually big                                       *
  *  - issue #3: the job fails with an out of memory issue       *
  *  - issue #4: if the input image copy contains the image copy *
  * of a non-partitioned table space and the unload specifies an *
  * ORDER clause, an ABENS0C4 occurs in function                 *
  * _inzzpiltBuilderAddFormating                                 *
  * When a job is affected by this issue, more than one message  *
  * INZX090 (up to one message per partitionned of the involved  *
  * table space) is issued for the unload from the image copy    *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Apply the PTF.                                               *
  ****************************************************************
  Code has been changed to fix this problem.
  

Problem conclusion

• Apply the PTF.
  

Temporary fix

• PH20972
  Depending on the issue, the following workaround can be
  considered:
   - issue #1: none but this is only a display issue.
   - issues #2 and #3: if applicable, as the problem is less acute
  when the number of involved partitions is not bigger than a few
  tens, consider splitting up the unload into several unload
  statements involving less partitions.
   - issue #4: use the DDLDDN option to provide Db2 HPU with the
  description of a non-partitionned object, or, if the sequence of
  the unload rows is not mandatory, remove the ORDER clause
  

Comments

APAR Information

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

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

  UI67646

Modules/Macros

• INZUTILK
  

Fix information

• Fixed component name

  DB2 HI PERF UNL

• Fixed component ID

  5697F4400

Applicable component levels

• R510 PSY UI67646

     UP20/02/05 P F002 {

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.