If there is already a database with the same name in
derby.system.home, an error will occur and the existing
database will be left intact. If there is not an existing database with the same
name in the current derby.system.home location, the system will
copy the whole database from the backup location to
derby.system.home and start it.
The log files are also copied to the default location. You can use the
logDevice attribute in conjunction with the
createFrom=path attribute to store logs in a different
location. With the createFrom=path attribute, you do not
need to copy the individual log files to the log directory.