Django should really have this built in ...

Safe Gigantic Django Queries

class IterableQuerySet(object):
              """Allows iteration over a QuerySet breaking it off into smaller chunks."""
              """Take from http://justcramer.com/2009/02/09/large-sql-result-sets-in-django/"""
              def __init__(self, queryset, batch=10000):
                  self.batch = batch
                  self.queryset = queryset
           
              def __iter__(self):
                  at = 0
           
                  results = self.queryset[at:at+self.batch]
                  while results:
                      for result in results:
                          yield result
                      at += self.batch
                      results = self.queryset[at:at+self.batch]