If you have an issue with it, bring it up with the HSQL team. It's not unusual to have it be > 1GB at times. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4004080#4004080 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=4004080