Using the Schema and Subschema Compilers › Output From the Compilers › Source Code and Load Modules

Source Code and Load Modules

Schema Definition

The schema compiler creates and maintains schemas in the DDLDML area of the dictionary in source form only; no schema load module ever exists. The schema is not used at runtime.

The dictionary can contain any number of schemas to define different versions of one database or to define several independent databases.

A schema is identified by a name and version number, the combination of which must be unique.

Subschema Definition

The subschema compiler creates subschemas in source and load module forms in the dictionary. Source is stored in the DDLDML area. Load modules are stored in the DDLDCLOD area.

Storing a Subschema Load Module in a Load Library

Optionally, you can store a subschema load module in a load library. To do this, perform the following steps:

1. Punch the load module using the subschema or DDDL compiler—Submit the PUNCH LOAD MODULE statement to obtain an object deck of the subschema.
2. Link edit the object deck into the load library—Execute the operating system's linkage editor, using as input the object deck produced by the PUNCH LOAD MODULE statement.

Load Modules at Runtime

At runtime, the subschema load module can reside in either the dictionary load area or a load library. If it resides in both places, CA IDMS/DB uses the first one it finds based on the loadlist and dictionary established for your session.

If you are using CA OLQ, you must keep the subschemas being accessed by CA OLQ in the dictionary load area.

Note: For more information about loading, see the CA IDMS System Generation Guide document.