Hi, in my opinion READ_COMMITTED is the correct level of isolation for optimistic locking. Morover in the forst post Tom contradicts himself anonymous wrote : The required isolation level should be set to REPEATABLE_READ for hibernate's optimistic locking to work correctly. That isolation level will guarantee that anonymous wrote : Non-Repeatable reads are a problem for optimistic locking and therefor, isolation level READ_COMMITTED is required if you configure more then 1 job executor thread What I think is the problem with Exceutors is that they report the StaleObjectExcepetion even if it is quite expected result in such case. Maybe for tables with jobs we should think about pessimistic locking as the conflicts can be quite frequent. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4160133#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...