MySQL索引失效十种场景与优化方案

CREATE TABLE `player` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT '主键',
  `player_id` varchar(256) NOT NULL COMMENT '运动员编号',
  `player_name` varchar(256) NOT NULL COMMENT '运动员名称',
  `height` int(11) NOT NULL COMMENT '身高',
  `weight` int(11) NOT NULL COMMENT '体重',
  `type` varchar(256) DEFAULT '0' COMMENT '球员类型',
  `game_performance` text COMMENT '最近一场比赛表现',
  PRIMARY KEY (`id`),
  KEY `idx_name_height_weight` (`player_name`,`height`,`weight`),
  KEY `idx_type` (`type`),
  KEY `idx_height` (`height`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8

@SpringBootTest(classes = TestApplication.class)
@RunWith(SpringJUnit4ClassRunner.class)
public class PlayerServiceTest {

    @Resource
    private PlayerRepository playerRepository;

    @Test
    public void initBigData() {
        for (int i = 0; i < 1000000; i++) {
            PlayerEntity entity = new PlayerEntity();
            entity.setPlayerId(UUID.randomUUID().toString());
            entity.setPlayerName("球员_" + System.currentTimeMillis());
            entity.setType("0");
            entity.setWeight(150);
            entity.setHeight(188);
            entity.setGamePerformance("{\"runDistance\":8900.0,\"passSuccess\":80.12,\"scoreNum\":3}");
            playerRepository.insert(entity);
        }
    }
}

explain select * from player where type = 0

explain select * from player where height + 1 > 189

explain select * from player where height > 188

explain select * from player where height > 187

explain select * from player where height > 188

update player set player_name = '测试球员' where id = 1

explain select * from player where player_name like '%测试'

explain select * from player where player_name like '%测试%'

explain select * from player where player_name like '测试%'

explain select * from player where type = '0' or weight = 150

explain
select * from player where type = '0' 
union
select * from player where weight = 150

explain select * from player where player_name like '测试%'

explain select id,player_name,height,weight from player where player_name like '测试%'

explain select * from player where player_name = '球员_1682577684751' and height = 188 and weight = 150

explain select * from player where player_name = '球员_1682577684751' and height = 188

explain select * from player where player_name = '球员_1682577684751' and weight = 150

explain select * from player where player_name='球员_1682577684751' and height > 188 and weight = 150

explain select * from player where weight = 150