You can set properties programmatically-either in application code
before booting the 
Derby driver or as a command-line option to the JVM
when booting the application that starts up 
Derby. When you set properties
programmatically, these properties persist only for the duration of the application.
Properties set programmatically are not written to the 
derby.properties file or made persistent in any other way by 
Derby.
 
Note: Setting properties programmatically works only for the application
that starts up Derby; for example, for an application in an embedded
environment or for the application server that starts up a server product.
It does not work for client applications connecting to a server that is running.