hibernate's objects eating up jboss's jvm heap

am seeing consistent Out of Memory Exceptions due to Hibernate objects consuming over 50% of the heap. (over 500M) Am using EntityManager for persistence

PersitanceBag and Collection Entry are some of them and there are some HashMaps as well contributed by Hibernate.

Please advise if there is any procedure to get rid of them after all the persistance.

Thanks in advance, cheers,

raj

EDIT:

will using em.clear() help or have any side effects?

EDIT 2:

em.clear() helped and dint have any 'side-effects'... there was a huge chunk of memory returned back to the heap after this call

the code is running in production environment for quite some time and em.clear is helping out without any side-effects...

thanks,

rajan