title: How to efficiently update more than one entity at a time on django-nonrel/app engine
body: <p>On django-nonrel on app engine, trying to use the "update" method on a QuerySet returns a NotImplementedError.  What is the most efficient way to do something like the following without using update?</p>
  
  <pre><code>goals = Goal.objects.filter(is_active=True).filter(deadline__lte=datetime.now())
  goals.update(is_active=False, is_failed=True)
  </code></pre>
  
  <p>I could obviously loop through the goals, modifying and saving them one by one, but that seems extremely inefficient when there could potentially be a large number that needs changing.  Any better way? </p>