I have added a version column to one of my model objects (and added the @Version tag). My application is multithreaded and when two threads try to modify the same model object in the same time, only one will succeed (which is what the versioning guarantees). Now, there are cases where the two threads are modifying two completely different columns and I would like that case not to fail with a StaleStateException.
- is having versioning not appropriate in this particular use case ?
- is there anyway to force hibernate to ignore the version number for a specific query ? (my query is changing one column which I know can be changed by only one thread, this assumption being guaranteed by design). Can the merge method be helpful in this case ?

I have been in a somewhat similar situation as you described. What I found worked best was to use an UPDATE statement that was executed against the database. See http://docs.jboss.org/hibernate/stable/ ... tch-direct for some more information.
I could use this because I knew that this particular property could only be updated by a specific piece of code.

You may also consider <class dynamic-update="true" optimistic-lock="dirty"> (or whatever the equivalent is with annotations). This is a more generic solution and will generate updates dynamically based on what properties that has changed.