Performance two keys a PK or

Databases
1

Hi,
What’s the best way


CREATE TABLE  `bookmark` (
  `user_id` int(10) unsigned NOT NULL,
  `video_id` int(10) unsigned NOT NULL,
  `date` datetime NOT NULL,
  PRIMARY KEY (`user_id`,`video_id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;
 

CREATE TABLE  `bookmark` (
  `id` int(10) unsigned NOT NULL,
  `user_id` int(10) unsigned NOT NULL,
  `video_id` int(10) unsigned NOT NULL,
  `date` datetime NOT NULL,
  PRIMARY KEY (`user_id`,`video_id`)
  KEY `index1` (`user_id`),
  KEY `index2` (`video_id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;

and why :slight_smile:

Thanks in advance.

2

the first one is better, because in the second one, the id column is useless