12.1.3 Derivation Method

Mandatory. Default= STATIC

Specifies how LANSA is to derive the system variable within a file I/O module or user written function that references it. You will enter the program identifier in Set Value by Calling (on IBM i) and Program Name (in the LANSA Editor).


Allowable values are:



The system variable is a static value, therefore its value can be derived once (during program initialization) by LANSA. Examples of static system variables would include the current job name, the current user name and most probably the current date (providing that applications do not normally span midnight while executing).



The system variable is a dynamic value, therefore its value must be derived each and every time it is referenced. Examples of dynamic system variables would include the current time, the current output queue name and library and all user defined system variables that "allocate" values such as the next invoice number, the next batch number, etc.

Note that every time a dynamic system variable is referenced the associated evaluation program is called to "refresh" the system variable. Excessive use of dynamic system variables with complex evaluation programs may degrade LANSA performance.