To answer #3, my read of the Hibernate code tells me that when Hibernate flushes the session that was in effect when addSession() was called, the node in JBC will be removed. When you subsequently read the collection, it will be loaded from DB and the putForExternalRead will be called. That read of the Hibernate code also ties to how I expected it to work. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4214618#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...