How to mix inheritance strategies with JPA annotations and Hibernate?

Question

According to the Hibernate Reference Documentation it should be possible to mix different inheritance mapping strategies when using Hibernate\'s XML-Metadata:
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Answer 1

Just for the sake of clarity, here is Pascal's solution applied to the example code from my question:

@Entity
@Inheritance( strategy = InheritanceType.SINGLE_TABLE )
@DiscriminatorColumn( name = "entityType", 
        discriminatorType = DiscriminatorType.STRING )
public abstract class A implements Serializable
{
    @Id
    private String id;

    // other mapped properties...
}

@Entity
@SecondaryTable( name = "BB" )
public class BB extends A
{
    @Basic( optional = false)
    @Column( table = "BB" )
    private String property1;

    // other mapped properties and associations...
}

@Entity
public class BB1 extends BB
{
    // other stuff, not necessarily mapped...
}

@Entity
public class BB2 extends BB
{
    // other stuff, not necessarily mapped...
}

@Entity
@SecondaryTable( name = "CC" )
public class CC extends A
{
    @ManyToOne( optional = false)
    @JoinColumn( table = "CC" )
    private SomeEntity association1;

    // other mapped properties and associations...
}

@Entity
public class CC1 extends CC
{
    // other stuff, not necessarily mapped...
}

...

I've successfully applied this approach to my problem, and I'll stick to it for the time being. However I still see the following disadvantages:

• The discriminator column is located in the main table for the hierarchy, the table for root-enity A. In my case, it would be sufficient to have the discriminator column in the secondary tables BB and CC.

• Anytime one adds properties and associations to subclasses of BB or CC, he/she has to specify that they should be mapped to the respective secondary table. Would be nice, if there was a way to make that the default.