In the previous chapters, we’ve just been using the JBoss default datasource in our applications. This is provided by the embedded HSQL database instance and is bound to the JNDI name java:/DefaultDS. Having a database included with JBoss is very convenient for running examples and HSQL is adequate for many purposes. However, at some stage you will want to use another database, either to replace the default datasource or to access multiple databases from within the server.