code: def blob(self, request, pk=None):
          
          obj = self.get_object_or_none()
          if obj:
              blob = obj.get_blob_data()
              content_type = 'octet/stream'
              response = HttpResponse(blob, content_type=content_type,
                                      status=status.HTTP_200_OK)
              response['Content-Disposition'] = (
                  'attachment; filename="%s"' % obj.name
              )
              return response
          return HttpResponse('404', status=status.HTTP_404_NOT_FOUND,
                              content_type='application/json')
docs: fetch large object from pg and gives it back to user via HTTP 1.1
          request
  
          :param request: django request instance
          :param pk: requested resource primary key
          :rtype: django.http.HttpResponse
          :rtype: HttpResponse
          :return: file with its filename stored in database