Hi, I used the "update " variant in the persistence.xml . I detected, that som things wont work with this option, for example, uniqueconstrains are not created correctly. For development the "create-drop" variant works fine. Deploying the application I have to update the schema in several databases. Is there a best practice how to do that. can hibernate create database scripts for the updates? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4020135#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...