First, the return here has nothing to do with "type of id". It has to do with the number of rows affected. Java's int has a maximum value of 2,147,483,647. If you are updating/deleting that many rows via Query#executeUpdate I think you have bigger problems

Besides, yes the type is dictated by JPA. We could make it long in the Hibernate Query contract and just deal with possible downcast issues when delegated from our JPA impls. But again, see above.