Hi, Im a j2ee developper & we are using hibernatne mapping with a postgres databasae. We have to keep track of any changes occurs in the databse , in others words alls previous & current value of any field should be saved & field can be various types (bytea, int, char...)

With a simple table it is easy but we a graph of objets things are more difficult

So we have , speaking in a UML point of view, a graph of objects to store in the database with every changes & the user.

Any idea or pattern how to do that ? Thanks in advance.