# File lib/innodb/system.rb, line 165
  def each_index_field_name_by_index_name(table_name, index_name)
    unless block_given?
      return enum_for(:each_index_field_name_by_index_name,
                      table_name, index_name)
    end

    data_dictionary.each_field_by_index_name(table_name, index_name) do |record|
      yield record["COL_NAME"]
    end

    nil
  end