Components in a COBOL Source File - Informatica

When you import a COBOL source, the Designer scans the file for the following components:

  • FD Section
  • Fields
  • OCCURS
  • REDEFINES

FD Section

The Designer assumes that each FD entry defines the equivalent of a source table in a relational source and creates a different COBOL source definition for each such entry. For example, if the COBOL file has two FD entries, CUSTOMERS and ORDERS, the Designer creates one COBOL source definition containing the fields attributed to CUSTOMERS, and another with the fields that belong to ORDERS.

Fields

The Designer identifies each field definition, reads the datatype, and assigns it to the appropriate source definition.

OCCURS

COBOL files often contain multiple instances of the same type of data within the same record. For example, a COBOL file may include data about four different financial quarters, each stored in the same record. When the Designer analyzes the file, it creates a different column for each OCCURS statement in the COBOL file. These OCCURS statements define repeated information in the same record. Use the Normalizer transformation to normalize this information.

For each OCCURS statement, the Designer creates the following items:

  • One target table when you drag the COBOL source definition into the Target Designer.
  • A primary-foreign key relationship
  • A generated column ID (GCID)

REDEFINES

COBOL uses REDEFINES statements to build the description of one record based on the definition of another record. When you import the COBOL source, the Designer creates a single source that includes REDEFINES.

The REDEFINES statement lets you specify multiple PICTURE clauses for the sample physical data location. Therefore, you need to use Filter transformations to separate the data into the tables created by REDEFINES.

For each REDEFINES:

  • The Designer creates one target table when you drag the COBOL source definition into the Target Designer.
  • The Designer creates one primary-foreign key relationship.
  • The Designer creates a generated key (GK).
  • You need a separate Filter transformation in the mapping.

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