Hi this is my table structure

CREATE TABLE IF NOT EXISTS `sms_report` (
 `R_id` int(11) NOT NULL auto_increment,
 `R_uid` int(11) NOT NULL,
 `R_smppid` varchar(100) collate utf8_unicode_ci NOT NULL,
 `R_from` varchar(10) collate utf8_unicode_ci NOT NULL,
 `R_status` longtext collate utf8_unicode_ci NOT NULL,
 `R_message` text collate utf8_unicode_ci NOT NULL,
 `R_numbers` longtext collate utf8_unicode_ci NOT NULL,
 `R_timestamp` timestamp NOT NULL default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP,
 `R_timedate` varchar(40) collate utf8_unicode_ci NOT NULL,
 `R_show` int(11) NOT NULL default '1',
 `oldformat` tinyint(1) NOT NULL default '0',
 PRIMARY KEY  (`R_id`)

) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci AUTO_INCREMENT=1947722 ;

I have approx 2 million rows so when I do an update on R_status here, it seem to take too long(R_status is either 1,2,16 or 24). Please suggest on how to optimise.

Originally asked by: Ashwin on Stack Overflow