Hibernate version 3.0
Database: Oracle 9i

Actually i couldnt get how about the inner process contained in dynamic-update="true" parameter. I would like to know how does hibernate detect which fields were modified and how does it mount dinamically the preparedStatement to analyse the performance costs, and decide which approach is better.

Thanks everyone.

Hibernate tracks the changes to mark the object dirty approrpiately. Dynamic update updates the individual fields rather than the whole record. Performance differences in general would not vary much between them but there will always be cases that may benefit either way, eg, Blobs a part of a record. You have the choice which is really great.