Question

I have three classes

 Class Company(models.Model):
     name     = CharField( max_length = 26 , blank = True)
     #(...)

 class Person(models.Model):
     name     = CharField( max_length = 26 , blank = True)
     function = CharField( max_length = 50 , blank = True)
     company  = ForeignKey ( Company , related_name = 'persons' )
     # All the company table inside the data base is loaded in order to make the query,
     # This make a HUGE amount of data and takes too many time...
     # (...)
     def __unicode__(self):
          # caption uses both name and company__name fields but no other fields
          return self.name + '(' + self.company.name + ')'

 class Contact(models.Model):
      person  =  ForeignKey ( Person )

In order to optimise performances, I would like the latest person field to use

Person.objects.all().only('name', 'company__name')

as queryset. Is it possible?

Answer 1

Use proxy models :

 class Person_short_manager(Manager):
    def get_query_set(self):
        return super(self, Person_short_manager).get_query_set().only('name','company__name')

 class Person_short(Person):
    objects = Person_short_manager(Manager)
    class Meta:
         proxy = True

then replace

 person  =  ForeignKey ( Person )

by

 person  =  ForeignKey ( Person_short )