Actually, i was surprised that this persistence.xml did not fail schema validation, because the "value" is a "required" attribute as per the xsd http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd. Looks like the xml validation is not triggered unless you add the following to your persistence.xml: <persistence | xmlns="http://java.sun.com/xml/ns/persistence" | xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" | xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd" | version="1.0"> So your persistence.xml should ultimately look like: | <?xml version="1.0" encoding="UTF-8"?> | | <persistence | xmlns="http://java.sun.com/xml/ns/persistence" | xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" | xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd" | version="1.0"> | | <persistence-unit name="mydb"> | | <jta-data-source>java:/XAOracleDS</jta-data-source> | | <properties> | | | <property name="dialect" value="org.hibernate.dialect.Oracle9Dialect"/> | | </properties> | View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4178227#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...