Writing a Navigational DML Program › Common Considerations

Common Considerations

Every program that uses navigational DML to access a CA IDMS database must do the following:

1. Identify the program's operating mode, the environment in which it will execute. Common operating modes are BATCH, BATCH-AUTOSTATUS, and IDMS-DC although many other environments are supported.
2. Identify the subschema, the program's view of the database to be accessed. The subschema must include all record types, set types, and areas required by the program.
3. Include descriptions of the IDMS communications block and the database records to be accessed. These descriptions are copied from the IDD into the program by the precompiler.
4. Detect and handle error conditions encountered during the execution of a DML function.