MODIFY Verb

System Generation Compiler › Adding, Modifying, and Deleting Entities › MODIFY Verb

MODIFY Verb

The MODIFY verb updates existing system and component entity definitions in the data dictionary. MODIFY also establishes currency for systems, lines, and physical terminals.

When modifying an entity, you must explicitly specify all characteristics that are to be changed. Characteristics not explicitly modified remain unchanged. Changes made to a system and its component entities are not reflected in the executable form of the system until you successfully generate that system with its changed characteristics. When any of the SYSGEN entities are modified, a GENERATE statement must be executed before recycling CV. If the SYSGEN is not successfully generated, the modified entities may not be recognized the next time CA IDMS CV is started.

The system generation compiler responds to MODIFY requests, as follows:

In response to a MODIFY SYSTEM request, the compiler updates the system source record with any explicitly specified characteristics. The next successful GENERATE statement for the system causes the compiler to copy information from the system source record into the system object record.
In response to a MODIFY statement for a component entity, the compiler updates the source record for the entity with any explicitly specified characteristics. The compiler also places update flags on all object records associated with the entity. A successful GENERATE statement for a system that includes the entity causes the compiler to copy information from the modified source record into the object record that connects the entity to the system.

What the Compiler does on a MODIFY

The following table illustrates system generation compiler actions in response to MODIFY requests.

Statements	Compiler Actions
MODIFY SYSTEM 20 MAX TASKS IS 15.	Sets system 20 current and modifies source record for system 20.
MODIFY TASK X DISABLED. (system 20 current)	Modifies source record for task X and flags all task X object records for update (U).
MODIFY TASK Y DISABLED. (system 20 current)	Modifies source record for task Y and flags all task Y object records for update (U).
GENERATE. (system 20 current)	Copies information from source record for system 20 to object record for system 20 and from source records for tasks X and Y to object records connected to system 20. Removes flags from updated object records.
MODIFY SYSTEM 30. GENERATE.	Sets system 30 current. Copies information from source record for system 30 to object record for system 30 and from source records for tasks X and Y to object records connected to system 30. Removes flags from updated object records.