Какие исключения следует ловить в SQLAlchemy?

def setup_connection():
	engine = create_engine("postgresql://postgres@localhost:5432/testdb", echo=False)
	Session = sessionmaker(bind=engine)
	sess = Session()
	try:
		Base.metadata.create_all(engine)
	except Exception as e:
		print("Could not initialize DB: {0}".format(e))
	return sess

session = setup_connection()