title: Django: Most efficient Many-To-Many-Relationship addition without through-model?
body: <p>I have to models:</p>
  
  <pre><code>class A(Model):
      b = models.ManyToManyField(B)
  
  class B(Model):
      # fields
  </code></pre>
  
  <p>What is the most efficient way to add a large number of existing instances of <code>B</code> to the relationship?</p>