PI05052: NEW FUNCTION OF APAR PM82937 TO SPECIFY PADDING CHARACTER CAN BREAK AN FSEAP

APAR status

• Closed as program error.

Error description

• APAR PM82937 provided a new function to specify a padding
  character when segment length is increased due to a DBD change.
  The padding process is invoked even when segment length is not
  increased and the process works incorrectly when a variable
  length segment or a compressed fixed length segment is defined.
  When a variable length segment or a compressed fixed length
  segment just fits the end of a block, the 1st byte of the FSEAP
  of the next block is broken by the padding character.  (The
  default padding character is X'00'.)
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of IBM IMS High Performance Load   *
  *                 for z/OS Version 2 Release 1 (FMID=H1IM210). *
  ****************************************************************
  * PROBLEM DESCRIPTION: Applying new function of APAR PM82937   *
  *                      can break an FSEAP.                     *
  ****************************************************************
  * RECOMMENDATION: Apply the maintenance for this APAR.         *
  ****************************************************************
  This APAR fixes the following two issues raised by APAR PM82937:
   1. Applying the APAR PM82937 can break an FSEAP, and a data
      loss can be caused by the broken FSEAP.
   2. WF1 records contain garbage when padding charecter other
      than X'00' is specified in the PAD statement.
  
  The details are as follows:
  1. APAR PM82937 provided a new function to specify a padding
     character when segment length is increased due to a DBD
     change. The padding process is even invoked when segment
     length is not increased and one of the following conditions
     is satisfied:
     - A segment edit/compression exit is used and the length of
       fixed-length segments is shorter than the maximum number of
       bytes that is defined by the COMPRTN parameter in the DBD
       definition.
     - The length of variable-length segments is shorter than
       the minimum segment length that is defined in the DBD
       definition.
  
     When the padding process is invoked and any of these segments
     are loaded right at the end of a block, the 1st byte of the
     FSEAP of the next block is broken by the padding character.
     (The default padding character is X'00'.)
     Inserting segment by using an incorrect FSEAP can cause loss
     of data.
  
  2. WF1 records contain garbage characters when all the following
     conditions are met:
     - APAR PM82937 has been applied and padding character other
       than X'00' is specified in the PAD statement.
     - Logical relationship or secondary index is defined for a
       compressed fixed-length segment and its length is increased
       during reorganization.
     - Unloaded data set is created in decompressed format.
  

Problem conclusion

• ========================
  = Documentation Change =
  ========================
  IMS High Performance Load for z/OS Version 2 Release 1 User's
  Guide SC18-9222-05 ( SC18922205 ) should be changed as follows:
  ================================================================
    2.1.5   Control statements
     :
    2.1.5.x PAD control statement
  |
  | Specifies the padding character to fill out the segments to
  | adjust to the length defined in the DBD definition.
  |
  | The segments are padded in the following cases:
  |   When a segment edit/compression exit is not used and the
  |   length of fixed-length segments is increased due to a change
  |   in the DBD definition.
  |
  |   When a segment edit/compression exit is used and the length
  |   of fixed-length segments is shorter than the maximum number
  |   of bytes that is defined by the COMPRTN parameter in the DBD
  |   definition.
  |
  |   When the length of variable-length segments is shorter than
  |   the minimum segment length that is defined in the DBD
  |   definition.
  |
    This control statement is optional. If you do not explicitly
    specify this control statement, PAD=X'00' is used.
  
       _________________________________________________________
      |                                                         |
      |                                                         |
      | >>__PAD=X'nn'____________________________________><     |
      |                                                         |
      |_________________________________________________________|
  
  
    nn
  |   Specify a two digit hexadecimal code as the padding
  |   character. For example, PAD=X'FF'.
  |
  | When all of the following conditions are met, the difference
  | in the segment length is padded with X'00' regardless of the
  | value specified on the PAD statement:
  |   Segments are defined as fixed-length segments.
  |   The use of a segment edit/compression exit is defined for
  |   the segments.
  |   The length of the segments is increased due to a change in
  |   the DBD definition.
  |   The unloaded data set is created in decompressed format.
  |
  

Temporary fix

• *********
  * HIPER *
  *********
  

Comments

APAR Information

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

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

  UI12507

Modules/Macros

• HPSRHDLA HPSRHDLB HPSRHDL2 HPSRHDL3 HPSRHDL7
  HPSRHDL8 HPSRHDL9 HPSRHSLA HPSRHSLB HPSRHSL2 HPSRHSL3 HPSRHSL7
  HPSRHSL8 HPSRHSL9 HPSRRLDA HPSRRLDB HPSRRLD2 HPSRRLD3 HPSRRLD7
  HPSRRLD8 HPSRRLD9
  

Fix information

• Fixed component name

  IMS HIGH PERF L

• Fixed component ID

  5655E0700

Applicable component levels