Hello, here's my case:

According to my domain model:
A School has many Students. and the relation is unidirectional

However when I use Set, adding a new student to a school causes entire students to be loaded.

If there are 1 million students, that's a big problem. In this sense , Sets are useless to me.

Using a bag is also useless. It is pretty troublesome if inverse = false and you add an item to your bag since it would truncate your table

Using and idbag is not possible. I've never seen a one-to-many mapping with idbag ?

So what to do ?

save the new student manually, if you don't need the object relationship immediately.

1) Save the Student object by itself,
2) and manually add the object to the School instance if you need it later to be part of School's set.

To avoid loading all 1mil Students automatically when you retrieve School, remember to declare in School.hbm.xml that its Student set is lazy.
Then it won't load all the Students until you explicitly call Hibernate.initialize().

1) Save the Student object by itself,
2) and manually add the object to the School instance if you need it later to be part of School's set.

To avoid loading all 1mil Students automatically when you retrieve School, remember to declare in School.hbm.xml that its Student set is lazy.
Then it won't load all the Students until you explicitly call Hibernate.initialize().