This illustration shows the object life cycle and the EclipseLink cache. Read requests from the database are sent to the persistence unit (session) cache in EclipseLink session. Write requests from the database are sent to the EclipseLink persistence context cache (also known as the unit of work cache). The persistence unit (session) cache registers objects with the unit of work. During a commit or merge transaction, the unit of work cache refreshes the persistence unit (session) cache.