Rails Ruby on Rails

class User < ActiveRecord::Base
  has_one :profile
end

class Profile < ActiveRecord::Base
  belongs_to :user
end

?> current_user.profile.user.profile.user.profile.user.profile
  User Load (0.4ms)   SELECT * FROM `users` WHERE (`users`.`id` = 4)
  Profile Load (0.1ms)   SELECT * FROM `profiles` WHERE (`profiles`.user_id = 4) LIMIT 1
  User Load (0.1ms)   SELECT * FROM `users` WHERE (`users`.`id` = 4)
  Profile Load (0.1ms)   SELECT * FROM `profiles` WHERE (`profiles`.user_id = 4) LIMIT 1
  User Load (0.1ms)   SELECT * FROM `users` WHERE (`users`.`id` = 4)
  Profile Load (0.1ms)   SELECT * FROM `profiles` WHERE (`profiles`.user_id = 4) LIMIT 1

This one-liner is obviously just an demonstration of the issue. The actual situation this was discovered in was a few user methods which call methods on the profile which call methods on the user, etc.

The reflections could be aware of the symmetry and connect the two objects, preventing further loading.