method returns DB cursor based on precise boundaries

def cursor_fine(self,
                    table_name,
                    start_id_obj,
                    end_id_obj,
                    iteration,
                    start_timeperiod,
                    end_timeperiod):
        """ method returns DB cursor based on precise boundaries """
        raise NotImplementedError('method cursor_fine must be implemented by {0}'.format(self.__class__.__name__))