Mapping provides CICS® VT with the information it requires to generate the driver modules that process the VSAM calls issued by your application programs. There are three parts to mapping.
The automated mapping facility analyzes the application copybook and automatically generates the DB2 DDL, the mapping data, and the runtime modules. The automated mapping facility also automatically maps alternate indexes, generates the DB2 DDL for the appropriate secondary indexes, and generates the CICS VT drivers. In the manual mapping method, you need to create the DDL, manually map the data set, and generate the runtime modules. You must identify each alternate index and manually map it using a CICS VT batch utility.
You cannot use the automated method if there is no copybook for the data set.
The automated mapping facility identifies copybook fields that may require a user action, such as truncated column names and redefined fields. You must action each identified field before you can continue the mapping process. The automated mapping facility does not support the mapping of one VSAM data set to more than one DB2 table.
If you map a file using the automated facility and decide to change the mapping at a later date, use the manual mapping facilities to make the changes. Making mapping changes to files that were mapped automatically may adversely affect alternate index mapping. You may have to make the same manual mapping changes to alternate index mappings for indexes that were initially mapped automatically.
For more information about automated mapping read The automated mapping facility . You should read this before you use the automated mapping facility to migrate a data set.
You must enable the ISPF mapping component before you can use either the manual or the automated mapping facility. This is covered in Implement the CICS VT ISPF interface .