public class TestGroup implements Serializable {
    private static final long serialVersionUID = 1L;
    
    @Id
    @Column(name = "TEST_GROUP_ID")
    private Integer testGroupId;
    
    @OneToMany(fetch = FetchType.LAZY)
    @JoinColumn(name = "TEST_GROUP_ID")
    private List<TestGroupRecipient> groupRecipients  = new ArrayList<TestGroupRecipient>();
}

public abstract class AbstractFacade<T> {
    private Class<T> entityClass;

    public AbstractFacade(Class<T> entityClass) {
        this.entityClass = entityClass;
    }

    protected abstract EntityManager getEntityManager();

    public T create(T entity) {
        getEntityManager().persist(entity);
        return entity;
    }

....

@Stateless
public class TestGroupFacade extends AbstractFacade<TestGroup> {
    @PersistenceContext(unitName = "OracleTest")
    private EntityManager em;

    @Override
    protected EntityManager getEntityManager() {
        return em;
    }

    public TestGroupFacade() {
        super(TestGroup.class);
    }
...

    @Inject
    private TargetGroupFacade targetGroupFacade;

...

TestGroup testgroup = testGroupFacade.find(ptestgroupId); // первый select 
List<TestGroupRecipient> list = testgroup.getGroupRecipients(); //  один раз выполняется select



...

// если  я сам добавляю - изменения :

 TestGroupRecipient recipient = testGroupRecipientFacade.find(recipientId);
 recipient.setRecipientId(null); // ID
 testGroupRecipientFacade.create(recipient);


testgroup.getGroupRecipients().add(recipient);
testGroupFacade.edit(testgroup); // видимо только так происходит обновление в кеше !?

            <property name="eclipselink.cache.shared.default" value="false"/>

            <property name="eclipselink.logging.level" value="ALL"/>
            <property name="eclipselink.logging.level.sql" value="FINE"/>
            <property name="eclipselink.logging.parameters" value="true"/>