Note: This is a newbie writing, this information may be incorrect and hence subject to change.
Notes on Geronimo's internal Derby installation:
- Geronimo's Derby installation runs in embedded mode, not client-server mode. That means that only processes running in the same JVM as Geronimo (e.g., its underlying web applications) can access Derby databases created from within Geronimo's Console application. In order to access a Derby database externally to Geronimo (e.g., using Derby's ij query tool) it would be necessary to shut down the Geronimo to release its lock on the database.
- Derby databases can be created external to Geronimo, running with Derby's network client software, and accessed in client-server mode. In this case, applications running on multiple JVM's can access the database. See the Derby website for more details.
- As explained in the link below, it is recommended for web applications using a pre-configured Derby database to use an EAR file, with the database compressed into a JAR file and kept separate from the WAR file. Next, using a Geronimo bean, the JAR file can be uncompressed and installed into the geronimo/var/derby directory (the usual location for embedded databases).