          """
          if chunk_size <= 0:
              raise ValueError('Chunk size must be strictly positive.')
          use_chunked_fetch = not connections[self.db].settings_dict.get('DISABLE_SERVER_SIDE_CURSORS')
          return iter(self._iterable_class(self, chunked_fetch=use_chunked_fetch, chunk_size=chunk_size))
  
      def aggregate(self, *args, **kwargs):
          """
          Return a dictionary containing the calculations (aggregation)
          over the current queryset.
 
</s> remove         for row in compiler.results_iter():
            yield row[0]
 </s> add         return chain.from_iterable(compiler.results_iter())
        return self._iterator(use_chunked_fetch, chunk_size)
          """
          if chunk_size <= 0:
              raise ValueError('Chunk size must be strictly positive.')
          use_chunked_fetch = not connections[self.db].settings_dict.get('DISABLE_SERVER_SIDE_CURSORS')
        return self._iterator(use_chunked_fetch, chunk_size)
  
      def aggregate(self, *args, **kwargs):
          """
          Return a dictionary containing the calculations (aggregation)
          over the current queryset.
keep keep keep keep replace keep keep keep keep keep
 Refs #28459 -- Improved performance of FlatValuesListIterable. 
django/db/models/query.py