Did you check: http://wiki.jboss.org/wiki/Wiki.jsp?page=ConfigDataSources ? Also, take a look at docs/examples/jca in your distribution. I don't know if Hypersonic supports XA or has an XA-aware Driver. I've used XA with MySQL 5.x before, but MyISAM doesn't support commit/rollback, so that defeats the purpose of transactional integrity; you'd have to opt for InnoDB or the new Falcon persistence engine. Any reason you need to keep Hypersonic around? For Production use you should be stripping this out anyway... S, ALR View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4139516#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...