You can invoke a program that does not return a value by using a CALL statement. You enclose arguments in parentheses, and they are passed by value. For example, suppose you create a simple program named addit to add two INTEGER values. You can use a CALL statement in the main program of your application to invoke the program.
You can also invoke programs in much the same way as you issue OLAP DML statements. You invoke user-defined functions in the same way as you use built-in functions. You merely use the program name in an expression and enclose the program arguments, if any, in parentheses. For a program that does not return a value (a user-defined command), you merely use the program name as you would an OLAP DML command. When you invoke a user-defined program as a function, the program returns NA.
You can also create programs that execute automatically when Oracle OLAP:
Executes an AW ATTACH. AW CREATE, AW DELETE, AW DETACH, DEFINE, MAINTAIN, PROPERTY, UPDATE, or SET statement as described in "Trigger Programs".
Encounters an NA value as described in $NATRIGGER.