When developing Derby applications,
create a single directory to hold your database or databases.
Give this directory a unique name, to help you remember that:
- All databases exist within a system.
- System-wide properties affect the entire system, and persistent system-wide
properties live in the system directory.
- You can boot all the databases in the system, and the boot-up times of
all databases affect the performance of the system.
- You can preboot databases only if they are within the system. (Databases
do not necessarily have to live inside the system directory, but keeping
your databases there is the recommended practice.)
- Once you connect to a database, it is part of the current system and thus
inherits all system-wide properties.
- Only one instance of Derby can
run in a JVM at a single time, and only one instance of Derby should
boot a database at one time. Keeping databases in the system directory makes
it less likely that you would use more than one instance of Derby.
- The error log is located inside the system directory.