The JBoss Messaging service (at least on JBoss 4.3 EAP) defaults to using a local Hypersonic database. For production use you’ll want to switch away from Hypersonic to a real database, such as Oracle (in this example).
If you’re using XA datasources in general, it’s tempting to go ahead and create the new DefaultDS datasource definition as an XA datasource (like the example one jboss-eap-4.3/docs/examples/jca/oracle-xa-ds.xml ). However, I’ve just discovered that if you do that the JMS startup service won’t successfully create the tables it needs. The HILOSEQUENCES and TIMERS tables get created by the UUID key generator service, but the JMS table creation silently fails and then you get errors like this: