Hibernate, is a fantastic tool, as long as it is not used in very high number of transactions. In our case for a transactional application, with a relatively complex data model, it is disastrous. It is one single hibernate insert, which is translated to 5 related sql inserts. Oracle 11g is the test database.
Database tools report less than ms for the real database work.
about 16 ms, is spent on oracle JDBC drivers. And guess how much is spent by hibernate.
about 90 ms.
I am working on it. Stay tuned.