Transparent Persistence with TopLink?

Question

I had the impression that TopLink allowed for 'transparent' persistence. I would expect, therefore, that I would be able to make persistent objects that have no reference to any TopLink classes/interfaces. The only reference to 'transparent' that I see in the documentation so far is for 'transparent indirection', which is not what I'm looking for.
Does TopLink support fully transparent persistence in this manner, and if so, where could I find documentation about this?
Thanks!

Answer 1

John,
Unfortunately this information is not concisely spelled out in our current documentation. The upcoming 9.0.4 documentation should address this deficiency by describing the modeling and requirements of your object model.
TopLink has always strived to be non-intrusive into the application's persistent model and it is completely possible to build a functional model that does not have ANY TopLink code in it.
The only commonly used performance optimization that may result in TopLink being intrusive into the object model is indirection on 1:1 relationships. For the collection relationships TopLink offers the transparent indirection that you found described in the documentation.
Unfortunately for 1:1 relationships it is not possible to be completely transparent without some sort of enhancements to your class (at present). TopLink's solutions to this are to provide proxy indirection, where you use an interface between the source and the target class (but still require no TopLink knowledge in the model) or you can use TopLink's ValueHolder interface to implement a simple proxy pattern.
So the short story is yes, TopLink can be completely transparent and non-intrusive ... but for the performance benefits of lazy loading on 1:1 relationships you must use proxy of value-holder indirection internally within your persistent model.
I hope this clarifies things for you,
Doug