Storing only one entity of bidirectional OneToOne relationship with Hibernate and Spring

Question

Situation :

• I'm using Spring (data) and Hibernate.
• I have to entities with a bidirectional @OneToOne relationship.
• Both share the same key (using @PrimaryKeyJoinColumn )

Problem :

• I want load A and B from the database
• I want to temporarily modify B (only in memory)
• I want to do calculations on B
• I want to store A, but not B

Formulated in code:

a = repositoryForA.findById(a);
b = a.getB();
a.setAttribute(abc);
b.setAttribute(xyz);
repositoryForA.save(a);

The behavior I see however is that always both A and B are stored (Verified with tests and hibernate log)

What I've tried :

• Detaching B before saving A before: entityManager.detach(b); repository.save(a) entityManager.detach(b); repository.save(a)
• No propagation @OneToOne(cascade={})
• Set a.setB(null) and detach before saving

Is this possible? Is the relationship maybe not good for this purpose?

Entities :

@Entity
public class A {

    @Id
    @GeneratedValue
    protected Long id;

    @OneToOne
    @PrimaryKeyJoinColumn
    private B b;

    // Some attributes...

}

@Entity
public class B {

    @Id
    protected Long id;

    @OneToOne(mappedBy = "b")
    @MapsId
    @JoinColumn(name = "id")
    private A a;

    // Some attributes...
    
}

Answer 1

I used a similar solution proposed by @K.Nicholas . I just created a copy of entity B to do the temporary calculations. I did not call repositoryForB.save(b) . So when saving a only the attributes of a itself were stored.