# File lib/generators/paper_trail/templates/create_versions.rb, line 9
  def change
    create_table :versions do |t|
      t.string   :item_type, :null => false
      t.integer  :item_id,   :null => false
      t.string   :event,     :null => false
      t.string   :whodunnit
      t.text     :object,    :limit => TEXT_BYTES

      # Known issue in MySQL: fractional second precision
      # -------------------------------------------------
      #
      # MySQL timestamp columns do not support fractional seconds unless
      # defined with "fractional seconds precision". MySQL users should manually
      # add fractional seconds precision to this migration, specifically, to
      # the `created_at` column.
      # (https://dev.mysql.com/doc/refman/5.6/en/fractional-seconds.html)
      #
      # MySQL users should also upgrade to rails 4.2, which is the first
      # version of ActiveRecord with support for fractional seconds in MySQL.
      # (https://github.com/rails/rails/pull/14359)
      #
      t.datetime :created_at
    end
    add_index :versions, [:item_type, :item_id]
  end