ActiveRecord Association Weird Length Method

The method 'length' defined for ActiveRecord associations works in a very weird manner.

consider this example


class User < ActiveRecord::Base
has_many :feeds
end


i was using the class and writing this snippet of code to get the count of feeds in the db


@user = User.find :first




puts @user.feeds.length


looking at the log, i found that the added query was


SELECT * FROM `feeds` WHERE (feeds.user_id = 1)


and not


SELECT count(*) AS count_all FROM `feeds` WHERE (feeds.user_id = 1)


so in order to get away from such weird sql statement which will exhaust a very large bandwidth getting all records to count them, use this instead


puts @user.feeds.count


or


puts @user.feeds.size


but don't use 'length' method