Transaction Processing - II
Transactions can be local or global.
A local transaction is managed by the resource manager while a global transaction is managed by a global transaction manager.
A global transaction in general interacts with more than one resource managers.
EJB spec only defines a flat transaction (not nested).
EJB requires that the EJB container supports the javax.transaction.UserTransaction interface defined in the Java Transaction API (JTA) for distributed transaction processing.