7.2 JVM Pooling Examples

Take for example an Oracle Forms application that has a user interface button. When the button is pressed, Oracle Forms takes the value from a field on the screen, and passes it to Java (using the Java Importer feature) to do some complex calculation which cannot be done in PL/SQL. The result is then returned and displayed in a field in the Form.

When JVM pooling is not enabled, the Forms Runtime Process operates as described in Figure 7-1, where each Oracle Forms session has its own instance of the JVM which is called an in-process JVM.

When JVM pooling is enabled, ideally, one JVM can be used for multiple Forms processes, as described in Figure 7-2:

In this example, five JVM instances have been reduced to one, thereby reducing memory usage.