Exclude models from the Rails identity map

gistfile1.txt

require 'active_record/identity_map'
module ActiveRecord
  module IdentityMap
    class << self
      alias_method :add_without_exclude, :add

      def exclusions
        @exclusions ||= []
      end

      def add(record)
        return if self.exclusions.include? record.class
        add_without_exclude(record)
      end
    end
  end
end