Hi,
I am just wondering what are the relations between sessionfactory and entitymanager. When using entitymanager in a container managed env. eg. using persistance.xml, will the entitymanager make use of the sessionfactory(is the entitymanager just a layer that makes use of the sessionfactory)? I was always used to using hibernate through the sessions, and my concern is if there will be any loss in performance/cache when using entitymanager instead of sessionfactory etc.

BR Soelvar

Look in the code if you're really interested, it's very straight forward. If you print out the class of your EntityManager you've been given by your container, you'll most likely find it's an org.hibernate.ejb.EntityManagerImpl, which is just a light wrapper around the Hibernate Session. Same deal for EntityManagerFactoryImpl and SessionFactory.

TL;DR
EntityManager == Session
EntityManagerFactory == SessionFactory.

Thanks for the reply Stolley,

So if I am understanding correctly, then with EntityManager you get the same benefits as when using Session, and the object obtained from queries are pojos instead of hibernate cglib wrapped non serializable classes, which kind of makes dto/vo obsolete - almost makes me wonder why anyone would use session/sessionFactory.