CA IDMS/DC Mapping Facility › Variable Array Processing

Variable Array Processing

Variable array records are records that contain a field that occurs a certain number of times depending on the value of another field in the record. An example is shown below:

SAMPLE-RECORD
03 FIELDA PIC S9(4) USAGE IS COMPUTATIONAL.
03 FIELDB PIC X(20) OCCURS 3 TO 10 TIMES
                    DEPENDING ON FIELDA.

Processing

When the external record of a file map includes a variable array, CA ADS Batch performs the following processing:

• On a mapin operation, the runtime system maps all fields included in the map definition into variable storage, even array fields that do not actually exist for the current input record. For example, in SAMPLE-RECORD, if FIELDB occurs seven times, the eighth, ninth, and tenth occurrences of FIELDB do not exist; however, the runtime system maps in whatever is in the record buffer for these occurrences. The record's control field (that is, FIELDA in the example), should be included in the map definition; otherwise, the field will not be mapped in and the application will not be able to distinguish the real data from the meaningless data in the array.
• On a mapout operation, the runtime system always maps out all fields that are included in the map definition, regardless of the value of the control field. The maximum record length for the map's associated external record is always written.

  Note: If a field contains meaningless data that cannot be mapped out successfully (that is, fails the automatic editing stage), the application aborts.