The function is mostly useful for commands that update the database:
           any result set returned by the query is discarded.

def _executemany(self, cursor, query, parameters):
        """The function is mostly useful for commands that update the database:
           any result set returned by the query is discarded."""
        try:
            self._log(query)
            cursor.executemany(query, parameters)
        except OperationalError as e:  # pragma: no cover
            logging.error('Error connecting to PostgreSQL on %s, e', self.host, e)
            self.close()
            raise