Do Django Model Managers require using=self._db
Managers use that parameter to define on which database the underlying queryset the manager uses should operate on. This is simply there to optionally override it in case you have e.g. multiple databases and you want your manger/queryset to operate on a specific one.
In working with the Django user model I've noticed model managers include a using=self._db parameter when acting on a database. If I'm only using a single database, is this necessary? What does using=self._db do other than specify the database. Is this specified as a fail-safe in the event another database is added?