Hi,

I played around with eager loading in order to tune the performance.
I used 'join fetch' in hql/criteria for loading some properties eagerly.
This works quite fine.

My problem is, that I want to avoid to have a cartesian product for
collections.
A sample:

Class A {
B b;
List<C> c;
}

Class B {
}

Class C {
D d;
}

Class D {
}

It is easy to load B when loading A, just use "from A a left outer join fetch a.b".
Eager loading c is not desired, because I want avoid having a cartesian product.

So my question: Can i tell hibernate to load D eagerly when hitting the Collection
List<C> for this session in advance? I do not want to configure this fetch mode
statically in class configuration.

I'm using Hibernate 3.3.5.ga.

Best regards,
Michi

Yes use extra-lazy collections.
Firstly make A.List<C> to be a lazy collection, secondly each C to be a lazy proxy with properties not loaded and finally C.D being loaded when you need it - assuming your session is still open.

Thank you for your reply.

Almost any property in my application is lazy. I do not want to load
entities I do not needed.
I search for something like following code fragment:


Thanks in advance,
Michi

<bag name="..." lazy="extra"/>
Or for annotations:
@LazyCollection(LazyCollectionOption.EXTRA)

Also the use of session.load() instead of session.get() has a subtle difference which might be of advantage.

O u meant instructing Hibernate during a runtime query to load the collection lazily but load a particular class of objects referenced by each member in that collection eagerly?
I doubt u could do that.

Thanks for your reply. That's exactly what I meant.