What's the use of session.flush() in Hibernate

Question

When we are updating a record, we can use session.flush() with Hibernate. What\'s the need for flush()?

Answer 1

Calling EntityManager#flush does have side-effects. It is conveniently used for entity types with generated ID values (sequence values): such an ID is available only upon synchronization with underlying persistence layer. If this ID is required before the current transaction ends (for logging purposes for instance), flushing the session is required.