Assuming a Java EE container is being used with JPA persistence and JTA transaction management where EJB and WAR packages are inside a EAR package.

Say an entity with lazy-load relationships has just been returned from a JPQL search, such as the getBoats method below:

@Stateless
public class BoatFacade implements BoatFacadeRemote, BoatFacadeLocal {

    @PersistenceContext(unitName = "boats")
    private EntityManager em;

    @Override
    public List<Boat> getBoats(Collection<Integer> boatIDs) {
        if(boatIDs.isEmpty()) {
            return Collections.<Boat>emptyList();
        }
        Query query = em.createNamedQuery("getAllBoats");
        query.setParameter("boatID", boatIDs);
        List<Boat> boats = query.getResultList();
        return boats;   
    }
}

The entity:

@Entity
@NamedQuery(
  name="getAllBoats",
  query="Select b from Boat b where b.id in : boatID")
public class Boat {
    @Id
    private long id;

    @OneToOne(fetch=FetchType.LAZY)
    private Gun mainGun;

    public Gun getMainGun() {
        return mainGun;
    }
}

Where will its lazy-load relationships be loadable (assuming the same stateless request):

1. Same JAR:
   • A method in the same EJB
   • A method in another EJB
   • A method in a POJO in the same EJB JAR
2. Same EAR, but outside EJB JAR:
   • A method in a web tier managed bean.
   • A method in a web tier POJO.
3. Different EAR:
   • A method in a different EAR which receives the entity through RMI.

What is it that restricts the scope, for example: the JPA transaction, persistence context or JTA transaction?