Unnecessary inner joins with super-classes in a JOINED inheritance hierarchy generated for a SUBSELECT fetch query in Hibernate

Issue

• An association is defined between entities X and C where C is a leaf-class in a JOINED inheritance hierarchy (C extends B which extends A).

• In the SQL below generated for a SUBSELECT fetch query, the inner join clauses (on B and A) are not needed to filter the result set since the association is defined at the leaf (between X and C) and no properties/columns of B nor A are referenced in the query.

  select
      x.property1, ...
  from
      X x
  where
      x.fk in (
          select c.id 
          from C c 
          inner join B b on c.id=b.id
          inner join A a on c.id=a.id 
          where c.something=?
      )