Thanks for your reply. I don't use native queries as my components are supposed to work, for example, both with SQLServer and MySQL. I change the mappings in persistence.xml and forget about which data base I am using. One of the reasons to work with all EJB overload is to be able to forget about native queries, isn't it? I guess I'll have to redesign client side to make the most of the relations "lazy". Thanks again, Ignacio View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4076183#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...