Calls with dependent segments for DEDBs
You can issue DL/I calls against direct and sequential dependent segments for DEDBs.
The DL/I calls that you can issue against a root segment are: GU,
GN (GNP has no meaning for a root segment), DLET,
ISRT, and REPL. You can issue all DL/I calls against a direct
dependent segment, and you can issue Get and ISRT calls against sequential
dependents segments.
Direct dependent segments
DL/I calls to direct dependents include the same number of SSAs as existing levels in the hierarchy (a maximum of 15). They can also include command codes and multiple qualification statements. The same rules apply to using command codes on DL/I calls to DEDBs as to full-function databases.
If you use the D command code in a call to a DEDB, the P processing option need not be specified in the PCB for the program. The P processing option has a different meaning for DEDBs than for full-function databases.
Some special command codes can be used only with DEDBs that use subset pointers. Your program uses these command codes to read and update the subset pointers.
Sequential dependent segments
Because sequential dependents are stored in chronological order, they are useful in journaling, data collection, and auditing application programs. You can access sequential dependents directly. However, sequential dependents are normally retrieved sequentially using the Database Scan utility.
- You can only use the F command code with sequential dependents; IMS ignores all other command codes.
- You cannot use Boolean operators in calls to sequential dependents.
Related reading: For more information about the utility, see IMS Version 15.2 Database Utilities.