<persistence-unit name="PU" transaction-type="JTA">
declare an JTA transaction entity manager (tansaction-type="JTA" is default), while
<persistence-unit name="PU" transaction-type="RESOURCE_LOCAL">
declares a resource-local transaction entity manager.
Ralph Jaus wrote:By the way (with fresh expressions from exam): It's good to have a clear understanding of the various types of entity managers (application managed vs. container managed, JTA vs. resource local transactions) and their persistence contexts (transaction scoped vs. extended).
I agree with this completely! For understanding this, I recommend PRO EJB3 Book, Chapter 5. MUST READ!