I've got a class that looks like this:

class Person
  include Mongoid::Document
  has_many :lots_of_freaking_documents, dependent: :delete
  # ^ about a 500k documents related to this person.
end

When I do this:

person = Person.find(...)
person.destroy

Instead of just deleting all of of the "lots_of_many_freaking_documents" based on the person_id field, Mongoid seems to be iterating through the "lots_of_many_freaking_documents" relationship, loading them and one by one removing them from the collection, which takes it a very, very long time.

Shouldn't Mongoid just be doing the equivalent of person.lots_of_many_freaking_documents.delete_all for this kind of dependent behavior? Am I missing something here with how this is supposed to work?