Hibernate has this info about the update setting anonymous wrote : Creates the database schema on deploy if it doesn't exist. Alters it if it has changed. Useful for when you want to generate database schema from entity beans The errors you're getting are because the schema and constraints already exist. Are you using Hibernate to generate the schema or did you do it manually? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4061355#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...