Hi, It's not something new as we checked that it was already the case with Hibernate 3.6 but we just hit an annoying problem with @OneToOne annotation if the relation is bidirectional. Simplified example: class A { @OneToOne(cascade = CascadeType.ALL, orphanRemoval = true) private B b; } class B { @OneToOne(mappedBy = "b") private A a; } If we insert 1 object in each table and we try to list the objects of A, the following queries are executed: 1. select a0_.id as id55_, a0_.b_id as b2_55_ from A a0_ 2. select b0_.id as id54_1_, a1_.id as id55_0_, a1_.b_id as b2_55_0_ from B b0_ left outer join A a1_ on b0_.id=a1_.b_id where b0_.id=1 3. select a0_.id as id55_1_, a0_.b_id as b2_55_1_, b1_.id as id54_0_ from A a0_ left outer join B b1_ on a0_.b_id=b1_.id where a0_.b_id=1 I don't understand the need for the third query. And this query quickly becomes a problem as it's executed for each EAGER @OneToOne relationship of A. In our application, we have a lot of @OneToOne relationships on an entity and a variant of the third query (which is big as the entity is big and the third query tries to populate all the EAGER relations) is executed for each @OneToOne of the base entity. I can provide more information if needed. I don't know if it's a limitation or a bug, that's why I haven't created a JIRA issue yet but I find this behaviour really suboptimal. As a temporary workaround, we made the @OneToOne relations unidirectional which makes our application usable again. Any pointers on where the problem could be or a confirmation that it's something expected? Thanks.

On Wed, Feb 29, 2012 at 7:50 PM, Steve Ebersole<steve(a)hibernate.org> wrote: > How are you loading these? Using Query#iterate I assume? We are using: entityManager().createQuery(query).getResultList(); and AFAICS in the stacktrace Query#list.