JR37511: Information Server; Reading from a table using the DB2 Connector may cause a downstream stage to fail with a nullability error

APAR status

• Closed as program error.

Error description

• Information Server; Reading from a table using the DB2 Connector
  may cause a downstream stage to fail with a nullability error
  when a column in the SELECT statement is a constant and is
  described as nullable in the columns grid.
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Jobs that use the DB2 Connector to read from a nullable column
  using a SELECT statement that returns a constant for the
  nullable column
  ****************************************************************
  PROBLEM DESCRIPTION:
  Reading from a table using the DB2 Connector may cause a
  downstream stage  to fail with a nullability error when a column
  in the SELECT statement is a constant and is described as
  nullable in the columns grid.
  
  If the DB2 Connector is used to read data from a column that is
  described as nullable in the job, but is considered NOT
  nullable by DB2 (at the time the job is run), then the
  downstream stage may report an error like:
  
       Message: main_program: When preparing operator: When
  setting up transfer
       for COLUMN_NAME:The source and destination have differing
  nullability.
  
  This scenario typically occurs when the SELECT statement uses a
  constant expression for one of the columns in the table.  For
  example, consider a  table with the following DDL:
  
       CREATE TABLE JR37511(COL1 VARGRAPHIC(1))
  
  On the Columns tab of the DB2 Connector stage, COL1 is a
  VarChar with the Extended attribute set to Unicode, and
  Nullable set to Yes.  The DB2 Connector's Generate SQL property
  is set to No and in the Select statement property the following
  statement has been entered:
  
       SELECT 'H' AS COL1 FROM JR37511
  
  At runtime DB2 will describe COL1 as NOT nullable, even though
  COL1 is nullable.  This is done because the SELECT statement
  will always return a constant ('H') for COL1.  The DB2 Connector
  then forces COL1 to be described as NOT nullable, which causes
  the error message mentioned earlier.
  ****************************************************************
  RECOMMENDATION:
  Apply patch JR37511
  ****************************************************************
  

Problem conclusion

• If the DB2 Connector is reading data and a column has Nullable
  set to Yes on the Columns tab, but DB2 describes the column as
  NOT nullable, then the DB2 Connector no longer forces the
  column to be described as NOT nullable.
  

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:

Modules/Macros

• SERVER
  

Fix information

• Fixed component name

  WIS DATASTAGE

• Fixed component ID

  5724Q36DS

Applicable component levels

• R810 PSN

     UP