Using the connection URL as described here, you can connect to databases
in more than one directory at a time.
Two examples:
jdbc:derby:../otherDirectory/myDB
jdbc::c:/otherDirectory/myDB
Once connected, such a database becomes a part of the system,
even though it is not in the system directory. This means that it takes on
the system-wide properties of the system and no other instance of should
access that database. It is recommended that you connect to databases only
in the system directory.