Someone set up this wiki page to describe the steps to convert DefaultDS to use MySQL: http://wiki.jboss.org/wiki/SetUpMysqlAsDefaultDS The steps for Oracle should be the same, though the details will change. (I haven't reviewed those steps in detail, and lately all of my work has been done with 5.0 where the steps to replace hsqldb with another database are somewhat different. In addition, I work with MySQL and PostgreSQL.) Essentially, the steps you outlined are correct. The catch is the DDL statements used by the various services. The wiki page you referenced details getting the messaging service DDL statements converted. But there are also tables for timers, hi-lo sequence tables, and transactions - you have run into issues with the first two, and looking at the last one I don't think that will be a problem. The issue is, of course, that different databases do not accept the same data types. But once you have corrected all of the tables, then you are done. By the way, one way to view all of the tables is to use the hsqldb-ds.xml file, and start and then stop the app server. The tables can be view in the file server/xxx/data/hypersonic/localDB.script. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4179428#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...