JR45872: Parallel transformers with many stage variables and complex derivations may compile with incorrect NULL checking code.

IBM InfoSphere Information Server, Version 9.1.2

APAR status

• Closed as program error.

Error description

• Problem:
  Stage variable in a Transformer stage are not being set to null,
  in very specific scenarios.
  
  Analysis:
  This problem is dependent on the size of the transformer stage
  i..e.., the size of the derivations of the stage variables or
  the output columns.
  It depends on the number of local variables that are created in
  the C++ file to handle the transformer stage.
  This problem was first seen on AIX. But it can
  create issues on another platforms.
  This issue can happen if the number of local variables
  created are more than 32.
  

Local fix

Problem summary

• tage variables in a Transformer stage are  not being set to
  null, in very specific scenarios.
  
  Problem description:
  A stage variable has the below derivation
  
  If Stream_070.ENSAI_FLG = "Y" Then
   2
  Else If Stream_070.ENSAI_FLG = "N" Then
   3
  Else
   SetNull()
  
  The stage variable is not being set to NULL, even when the input
  field ENSAI_FLG is not 'Y' or 'N'.
  This is happening only when the the input and output schemas of
  the transformer stage are considerably big and when the
  derivations on the stage variables or the output fields are
  complex.
  Analysis:
  This problem is dependent on the size of the transformer stage
  i..e.., the size of the derivations of the stage variables or
  the output columns.
  It depends on the number of local variables that are created in
  the C++ file to handle the transformer stage.
  This problem is being particularly seen in AIX. But it can
  create issues on another platforms as well.
  This issue is being seen if the number of local variables
  created is  more than 32.
  

Problem conclusion

• nalysis:
  This problem is dependent on the size of the transformer stage
  i..e.., the size of the derivations of the stage variables or
  the output columns.
  It depends on the number of local variables that are created in
  the C++ file to handle the transformer stage.
  This problem is being particularly seen in AIX. But it can
  create issues on another platforms as well.
  This issue is being seen if the number of local variables
  created are more than 32.
  
  This issue is related to the functions handling nullability of
  local variables in functions
  inline bool isLocalNull(APT_UInt64 offset)
  
  
  inline void setLocalNull(APT_UInt64 offset)
  inline void clearLocalNull(APT_UInt64 offset)
  
  This issue was introduced in IIS 8.5.
  

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:

Fix information

• Fixed component name

  WIS DATASTAGE

• Fixed component ID

  5724Q36DS

Applicable component levels

• R850 PSY

     UP

• R870 PSY

     UP

• R910 PSY

     UP