temp.rb

class User
  include Mongoid::Document
  field :name
end

users = User.all.cache
users.each { |u| puts u } # Database hit
users.each { |u| puts u } # No database hit

class Post
  include Mongoid::Document
  cache

  field :name
  embeds_many :comments
end

posts = Post.all
posts.each { |p| puts p } # Database hit
posts.each { |p| puts p } # No database hit (even for the comments)

class Doctor
  include Mongoid::Document
  cache

  references_many :patients
end


doctors = Doctor.all
doctors.each { |d| puts d } # Database hit
doctors.each { |d| puts d } # Not really sure? Is this a database hit for the references?


def users
  User.all.cache
end

def index
  if users.count > 5 # Database hit
    render_for(users) # Database hit because we're defining a new
    criteria
  else
    ...
  end
end