  void set_column_format(column_format_type column_format_arg)
  {
    DBUG_ASSERT(column_format() == COLUMN_FORMAT_TYPE_DEFAULT);
    flags |= static_cast<uint32>(column_format_arg) <<
      FIELD_FLAGS_COLUMN_FORMAT;
  }
  void set_column_format(column_format_type column_format_arg)
  {
    DBUG_ASSERT(column_format() == COLUMN_FORMAT_TYPE_DEFAULT);
    flags |= static_cast<uint32>(column_format_arg) <<
      FIELD_FLAGS_COLUMN_FORMAT;
  }