When I just installed JBoss it was configured to use Oracle. However, JBoss Portal did not work immediately. I needed to perform the following steps: 1. Copy the Oracle JDBC jar file to [JBOSS.HOME]/server/default/lib. 2. Create database sequences: create sequence hibernate_sequence; create sequence portal_seq; create sequence sec_seq; create sequence instance_seq; create sequence portlet_seq; create sequence user_seq; I'm not sure when Hibernate didn't create these sequences automatically. I may be an issue specific to Oracle since I don't recall the same problem when using other databases. UPDATE: JBoss Portal did not automatically create the sequences because I did not copy the Oracle JDBC jar file into the JBOSS.HOME/lib directory immediately after the installation process completed.