Hello, I was thinking about REPEATABLE_READ isolation level with optimistic locking and it seems to me that it can not work. In docs there is written that anonymous wrote : Non-Repeatable reads are a problem for optimistic locking and therefore isolation level READ_COMMITTED is not enough cause it allows for Non-Repeatable reads to occur. So REPEATABLE_READ is required if you configure more than one job executor thread. | But I found here http://www.avaje.org/occ.html that anonymous wrote : It is important to note that Optimistic Concurrency Checking only works in READ_COMMITED Transaction Isolation Level. Specifically, at higher Isolation levels such as SERIALIZABLE the UPDATE or DELETE will see the database as at the Transaction start time. In the time gap between Transaction start time and the UPDATE/DELETE statement there could be commited changes that will be lost (Lost Updates). I think b.) is right, it makes sense. jBPM docs are not correct, am I right? Your docs confused me. Pavel View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4158934#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...