Java Persistence/What is new in JPA 2.0?

The JPA 2.0 specification adds several enhancements to the JPA 1.0 specification including:
 * Extended Map support - Support for maintaining a key column for a,  , or   key value in any collection relationship using a.
 * Derived Identifiers
 * Nested embedding
 * New collection mappings - Support for collections of  or   types.
 * Undirectional OneToMany
 * Ordered List mappings - Support for maintaining an index column in any collection relationship using a.
 * Orphan removal - Automatic deletion of objects removed from relationships.
 * Pessimistic Locking
 * EntityManager API updates
 * Cache APIs
 * Standard Properties
 * Metadata
 * Criteria API
 * JPQL enhancements

Resources

 * JPA 2.0 Spec
 * JPA 2.0 Reference Implementation (EclipseLink)
 * Eclipse EclipseLink to be JPA 2.0 Reference Implementation
 * JPA 2.0 Examples

/What is Java persistence