CREATE TABLE `maintable` (
  `table_id` int(11) NOT NULL auto_increment,
  `field1` int(11) NOT NULL default '0',
  PRIMARY KEY  (`table_id`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=40001 ;

CREATE TABLE `subtable` (
  `table_id` int(11) NOT NULL auto_increment,
  `field1` int(11) NOT NULL default '0',
  `field2` int(11) NOT NULL default '0',
  PRIMARY KEY  (`table_id`),
  KEY `index_two_fields` (`field1`,`field2`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=5001 ;