code: def _executemany(self, cursor, query, parameters):
          
          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
docs: The function is mostly useful for commands that update the database:
             any result set returned by the query is discarded.