JR59186: When DB2 Connector uses Derivation the columns mismatch occurs and the job aborts with error

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APAR status

• Closed as program error.

Error description

• When in DB2 Connector the Derivation is specified for a column
  to return the result of an expression, schema reconciliation
  fails as the column's name cannot be matched with the result of
  an expression named like eg.: EXPR1.
  In case of migration from DB2API to DB2CC, despite the
  Derivation expression is correctly migrated, a job aborts.
  The cause of this issue is that binding by Name is done (by
  default).
  Job aborts with error:
  CopyOfpmrCount1..DB2_Connector_0: Schema reconciliation failed:
  The column names defined on the link do not match those of the
  external resource
  CopyOfpmrCount1..DB2_Connector_0.DSLink2: DSP.Open GCI
  $DSP.Open error -100.
  CopyOfpmrCount1..Sequential_File_1.IDENT1:
  |CopyOfpmrCount1..DB2_Connector_0.DSLink2: DSP.Open GCI
  $DSP.Open error -100.|
  

Local fix

• If we specify an alias, the column is matched by its name and
  job runs OK - the issue is not reproduced.
  Another way to make it work, instead of using alias, is to use
  the DB2 Connector's property "Prefix for expression columns",
  which by default is EXPR.
  

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Users of DB2 Connector stage on Server Canvas, using Derivation
  for a column.
  ****************************************************************
  PROBLEM DESCRIPTION:
  When in DB2 Connector the Derivation is specified for a column
  to return the result of an expression, schema reconciliation
  fails as the column's name cannot be matched with the result of
  an expression named like eg.: EXPR1.
  In case of migration from DB2API to DB2CC, despite the
  Derivation expression is correctly migrated, a job aborts.
  The cause of this issue is that binding by Name is done (by
  default).
  ****************************************************************
  RECOMMENDATION:
  Apply the patch JR59186
  ****************************************************************
  

Problem conclusion

• Implemented the code change in DB2 Connector so when a column
  Derivation is used, columns are binded by Position.
  As a result, the job with Derivation does not abort and the
  migrated job works without any changes.
  However, when "Prefix for expression columns" (EXPR) is used in
  the column name - the default binding by Name is performed to
  keep previous behavior in this case.
  

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

• RB50 PSY

     UP