Maximum Forms

maximum forms nn

where nn is the number of recently used forms stored in memory for each window

The maximum forms option enables you to control the buffering of forms definitions in memory. You can use as many forms as desired during a session but, for each window, only the nn most recently used forms are kept in memory. The value of nn must be a least as large as the number of forms in the largest display in the application. In addition, nn should compensate for the number of forms and displays saved using the FORM SAVE command.

Unlike other types of buffering, maximum forms is defined in terms of the number of forms stored rather than as an absolute amount of memory. Therefore, the actual amount of space used can vary greatly (e.g., one form with one field occupies less space than one form with five fields).

Each open window has its own separate buffer area for form definitions. A form enters the buffers controlled by maximum forms when it is opened directly or as part of a display object. Forms that are in the currently open display, or those that have been saved using a FORM SAVE command, cannot be removed from the buffer. However, a form that is not in the currently open display, or that has not been saved, can be removed and replaced by newly opened forms.

The best setting for maximum forms is based on

• the maximum number of forms in any display in the application

• the maximum number of forms that could be saved at any time

Generally, the maximum forms option should be set to the sum of these two numbers. A slightly lower value can be used if the maximum number of saved forms does not coincide with the largest display being open. The setting can be restricted if the application is being run in a memory-limited environment.

A convoy problem is possible. If the maximum forms option is set at 5, for example, but part of the application cycles through six forms, the forms shuttle through the buffer, negating the benefits the option.

Valid Settings

nn = numeric entry 1 to 64