It still selects all fields by default. Very often I have to use defer() or only() to get rid of expensive columns like blob/text that are rarely used and greatly hurt performance when grabbing them.

Then it got to where I had to make a reflective function that I use like Model.objects.defer(*all_fields_except(Model, ['field1', 'field2'])), and then add another all_fields_except() for every select_related and prefetch_related.

Even save() by default re-writes every single field. You have to use save(update_fields=['field1']) instead.