I just cleaned up all the unnecessary/incorrect merges in my application, now the memory footprint is noticeably smaller. Thank Christian again for correcting me. Unfortunately my original problem is not solved yet. I cannot seem to do flush in the @Destroy@Remove method, thus the removal of the incomplete motherEntity cannot be reflected in the database, the data integrity is harmed if any user leaves the conversation without explicitly ending it (either complete or cancel), or the server has a reboot when a conversation is in process....this is a pretty critical problem. I tried explicit deletion using EQL in the @Destroy@Remove method too, it did not help. The concrete error messages I got were always something like "no transaction available", still seeking a solution....Any suggestion will be highly appreciated! View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4064097#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...