Can somebody please explain what a Persistence Unit actually is ?
SCJP 5.0, SCWCD 1.4, SCJA 1.0
posted 9 years ago
JSR 220 explains this very clearly.
A persistence unit is a logical grouping that includes: � An entity manager factory and its entity managers, together with their configuration information. � The set of managed classes included in the persistence unit and managed by the entity managers of the entity manager factory. � Mapping metadata (in the form of metadata annotations and/or XML metadata) that specifies the mapping of the classes to the database.