A Derby database
contains dictionary objects such as tables, columns, indexes, and jar files.
A Derby database can also
store its own configuration information.
The database directory
A Derby database is stored in files that live in a directory of the same name as the database. Database directories typically live in system directories.
Single database shutdown
An application can shut down a single database within a Derby system and leave the rest of the system running.
Storage and recovery
A Derby database (unless it is an in-memory database) provides persistent storage and recovery. Derby ensures that all committed transactions are durable, even if the system fails, through the use of a database transaction log.
Log on separate device
You can put a database's log on a separate device when you create it.
Database pages
Derby tables and indexes, known as conglomerates, consist of two or more pages.
Database-wide properties
You can set many Derby properties as database-level properties. When set in this way, they are stored in the database and "travel" with the database unless overridden by a system property.