SQL/MX 3.2.1 Guide to Stored Procedures in Java (H06.26+, J06.15+)

loads an application class, the class loader creates and manages a new copy of the application
class and its static variables. For an example, see Figure 8 (page 31).
Figure 8 Copies of Java Classes in SPJ Class Loaders
If an application class does not change on disk during an active SPJ environment, identical copies
of the application class exist in memory and could waste resources. To conserve system resources,
design your Java classes and directory structure so that fewer SPJ methods in different external
paths rely on the same application class.
If an application class changes on disk during an active SPJ environment, copies of old and new
versions of the application class could be in memory at the same time, leading to unpredictable
and undesirable behavior of CALL statements. To prevent this problem, stop the calling application,
which ends the SQL/MX UDR server process, install the updated class or JAR file, and then restart
the application.
The SPJ Environment 31