Introduction The Persistence Context acts as a transactional-write behind cache for the incoming entity state transitions, and all changes are synchronized with the database during flushing. Although both the Hibernate Session and the JPA EntityManager define a flush() method to manually trigger this process, it’s much more convenient to let Hibernate manage the Persistence Context flushing. Unfortunately, there’s is a major difference between how JPA and Hibernate define the automatic flushing mechanism.