"Mussie" wrote : Can't I use HSQL DB why mysql? Yes, just configure a HSQL in persistent mode in -ds.xml anonymous wrote : And whats the sence of update if I have to validate the database? | I thought hibernate generates the db relations out of my entities? Then use create-drop, but loose your data, or use update. anonymous wrote : And why are all the examples with in memory based persistence I can't picture any use-case for that. Because it's great for examples. Read the hsql docs, its a 2 line change to make it persistent, and without the tables being create-droped. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4117474#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...