Why does a query invoke a auto-flush in SQLAlchemy?

How to turn off autoflush feature:

• Temporary: you can use no_autoflush context manager on snippet where you query the database, i.e. in X.test method:

  def test(self, session):
      with session.no_autoflush:
          q = session.query(X).filter(X._val == self._val)
          x = q.one()
          print('x={}'.format(x))
  

• Session-wide: just pass autoflush=False to your sessionmaker:

  return sao.sessionmaker(bind=engine, autoflush=False)()