Java DB

Apache Derby

Derby Developer's Guide

Derby Getting Started
Derby Reference Manual
Derby Developer's Guide
Derby Performance Tuning
Derby Server and Admin Guide
Derby Tools and Utilities
Derby Developer's Guide
-After installing
-Upgrades
-JDBC applications and Derby basics
-Application development overview
-Derby embedded basics
-Derby JDBC driver
-Derby JDBC database connection URL
-Derby system
-A Derby database
-Connecting to databases
-Working with the database connection URL attributes
-Using in-memory databases
-Working with Derby properties
-Deploying Derby applications
-Deployment issues
-Creating Derby databases for read-only use
-Loading classes from a database
-Derby server-side programming
-Programming database-side JDBC routines
-Programming trigger actions
-Programming Derby-style table functions
-Programming user-defined types
-Controlling Derby application behavior
-The JDBC connection and transaction model
-Result set and cursor mechanisms
-Locking, concurrency, and isolation
-Working with multiple connections to a single database
-Working with multiple threads sharing a single connection
-Working with database threads in an embedded environment
-Working with Derby SQLExceptions in an application
-Using Derby as a J2EE resource manager
-Derby and Security
-Configuring security for your environment
-Working with user authentication
-Users and authorization identifiers
-User authorizations
-Encrypting databases on disk
-Signed jar files
-Notes on the Derby security features
-User authentication and authorization examples
-Running Derby under a security manager
-Developing tools and using Derby with an IDE
-SQL tips
-Localizing Derby
-Derby and standards

 

One Derby instance for each Java Virtual Machine (JVM)

You could potentially have two instances of a Derby system running on the same machine at the same time. Each instance must run in a different Java Virtual Machine (JVM).

If you use the embedded driver, two separate instances of Derby cannot access the same database. If a Derby instance attempts to access a running database, an error message appears, and a stack trace appears in the derby.log file. If you want more than one Derby instance to be able to access the same database, you can use the Network Server.

If a Derby instance uses the in-memory database capability for its database connection, the database exists only within the JVM of that Derby instance. Another Derby instance could refer to the same database name, but it would not be referring to the same actual database, and no error would result.

Related concepts
 

javadb@jdbcurl.com