SELECT COUNT(*) FROM `comment` SHOW CREATE TABLE `comment`CREATE TABLE `comment1` (  `id` INT(8) NOT NULL AUTO_INCREMENT,  `blogUser` VARCHAR(20) NOT NULL,  `replayUser` VARCHAR(20) NOT NULL,  `articleId` INT(8) NOT NULL DEFAULT '0',  `content` TEXT,  `addTime` DATETIME NOT NULL,  PRIMARY KEY (`id`),  KEY `addTime` (`addTime`),  KEY `replayUser` (`replayUser`)) ENGINE=MYISAM AUTO_INCREMENT=1000004 DEFAULT CHARSET=utf8INSERT INTO comment1 SELECT  `id` ,  `blogUser`,  `replayUser`,  `articleId` ,  `content` ,  `addTime`FROM `comment` LIMIT 0,500003CREATE TABLE `comment2` (  `id` INT(8) NOT NULL AUTO_INCREMENT,  `blogUser` VARCHAR(20) NOT NULL,  `replayUser` VARCHAR(20) NOT NULL,  `articleId` INT(8) NOT NULL DEFAULT '0',  `content` TEXT,  `addTime` DATETIME NOT NULL,  PRIMARY KEY (`id`),  KEY `addTime` (`addTime`),  KEY `replayUser` (`replayUser`)) ENGINE=MYISAM AUTO_INCREMENT=1 DEFAULT CHARSET=utf8INSERT INTO comment1 SELECT  `id` ,  `blogUser`,  `replayUser`,  `articleId` ,  `content` ,  `addTime`FROM `comment` LIMIT 500003,60000000CREATE TABLE `allcomment` (  `id` INT(8) NOT NULL AUTO_INCREMENT,  `blogUser` VARCHAR(20) NOT NULL,  `replayUser` VARCHAR(20) NOT NULL,  `articleId` INT(8) NOT NULL DEFAULT '0',  `content` TEXT,  `addTime` DATETIME NOT NULL,  PRIMARY KEY (`id`),  KEY `addTime` (`addTime`),  KEY `replayUser` (`replayUser`)) ENGINE=MERGE UNION (comment1, comment2) INSERT_METHOD=LAST AUTO_INCREMENT=1 ; SELECT COUNT(*) FROM `allcomment`