mysql插入索引表后需要很长时间才能记录几百万条记录

I have a table like this

我有一张这样的桌子

CREATE TABLE IF NOT EXISTS `dnddata` (
  `numbers` varchar(10) NOT NULL,
  `opstype` char(1) NOT NULL,
  PRIMARY KEY (`numbers`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1
/*!50100 PARTITION BY KEY (numbers)
PARTITIONS 25 */;
CREATE T