The Real Purpose of DBDGEN Utility in IMS DB

Here’s the purpose of DBDGEN in IMS DB. The DBDGEN utility generates DBDs for a database based on the type of database being used.

DBDGEN Utility Control Statements

The DBD statement names the database being described and provides DL/I with information concerning database organization.

The DATASET statement is used only in non-DEDB DBDGEN input record structures. The DATASET statement defines a data set group within a database. One or more DATASET statements follow the DBD statement.

The AREA statement is used only in DEDB DBDGEN input record structures. The AREA statement defines an area within a database. One or more AREA statements follow the DBD statement.

The SEGM statement defines the segments of the specified database. The SEGM statement is used with the following statements:

FIELD
XDFLD
LCHILD
DFSMARSH
DFSMAP
DFSCASE

Each statement defines different aspects of a segment or the fields in a segment. The DBDGEN statement indicates the end of DBDGEN control statements. FINISH is an optional statement retained in the input stream for compatibility.

The END statement indicates to the z/OS® assembler that the end of the input statements has been reached. More on DBD-Database Description Utility.