title: Use Django with MongoDB and PostgreSQL at the same time
body: <p>I have project written on Django Rest Framework. When i started project, i was using just PostgreSQL as main database. Now i need to use MongoDB as main database, but i faced with problem: framework that i used for authentication <a href="https://github.com/Tivix/django-rest-auth" rel="nofollow noreferrer">rest-auth</a>, maybe should not work properly with MongoDB. So i have two questions:</p>
  
  <p>1)Is it possible(i am asking about good practices) to use one database for users authentication, and another for business logic</p>
  
  <p>2)If answer on first is "yes", can i referencing from MongoDB Model to PostgreSQL model? Something like that:</p>
  
  <pre><code> class ToolInput(EmbeddedDocument):
   name = fields.StringField(required=True)
   user = fields.ReferenceField(User)
  </code></pre>
  
  <p>User - model that stored in PostgreSQL
  settings.py stores connection to both databases :</p>
  
  <pre><code>DATABASES = {
  
  'default': {
      'ENGINE': 'django.db.backends.postgresql_psycopg2',
      'NAME':
      'USER':
      'PASSWORD':
      'HOST':
      'PORT': '5432',
      'CONN_MAX_AGE': 15000,
  } 
  
  mongoengine.connect(
  db="tools",
  host="localhost")
  </code></pre>
  
  <p>Sorry if this is duplication,but i didnt found nothing about this</p>