bigdir/db/migrate/20091017212644_add_missing_indexes_to_messages.rb

class AddMissingIndexesToMessages < ActiveRecord::Migration
  def self.up
    add_index :messages, :last_reply_id
    add_index :messages, :author_id
  end

  def self.down
    remove_index :messages, :last_reply_id
    remove_index :messages, :author_id
  end
end