Seamless ActiveRecord Model extension
The Problem What if you have one very bloated model, like User, that has a ton of fields you use only once or twice in your whole application and yet paying price for it every time you fetch / create a new one. In this case what you want is to move some of these fields to another model (e.g. profile or user details). The Solution First step is to generate another model, let's name it UserProfile and link it to User model. You would also have to run a migration that adds UserProfile to all existing users. Now what you can do is to write something like: Now, of course, we could stop there, but why miss all the fun? What we want to do instead is: So how do we do that? Performance When I measured how speed and memory footprint correspond to number of columns I found that both increase roughly linear as number of columns grows. Precautions When mass-assigning attributes from controller while using CanCan gem (tested in Rails 3.2), e.g. (User.new(params[:user])), CanCan...