hibernate session.save() does not reflect in database

Question

According to my understanding in hibernate (please confirm)

1- You have to session.close() if you get it by getSessionFactory().openSession()

Answer 1

if there is DB manipulation operation then it should be in transaction
if you call session.save(object)
hibernate create bellow query only .
select hibernate_sequence.nextval from dual
so right code is here
Transaction  t=session.beginTransaction();
session.save(obect);
t.commit(); should not forgot to commit.
session.close();