Invoking a single SQL program through ISPF and DSN

When you invoke a single SQL program through ISPF and DSN, you should first invoke ISPF, which displays the data and selection panels. When you select the program on the selection panel, ISPF calls a CLIST that runs the program.

About this task

A corresponding CLIST might contain:

DSN
    RUN PROGRAM(MYPROG) PLAN(MYPLAN)
END

The application has one large load module and one plan.

Disadvantages: For large programs of this type, you want a more modular design, making the plan more flexible and easier to maintain. If you have one large plan, you must rebind the entire plan whenever you change a module that includes SQL statements. To achieve a more modular construction when all parts of the program use SQL, consider using packages. See DB2 program preparation overview You cannot pass control to another load module that makes SQL calls by using ISPLINK; rather, you must use LINK, XCTL, or LOAD and BALR.

If you want to use ISPLINK, then call ISPF to run under DSN:

DSN
    RUN PROGRAM(ISPF) PLAN(MYPLAN)
END

You then need to leave ISPF before you can start your application.

Furthermore, the entire program is dependent on DB2; if DB2 is not running, no part of the program can begin or continue to run.

Parent topic: Invoking programs through the Interactive System Productivity Facility