mysql update 等值 锁区间

CREATE TABLE `p300` (
  `sn` int(11) NOT NULL AUTO_INCREMENT,
  `uuid` int(11) NOT NULL,
  `mobilePhone` int(11) NOT NULL,
  PRIMARY KEY (`sn`),
  KEY `p100_idx1` (`uuid`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8

mysql> insert into p300 select sn,sn,mobilePhone from p300;
Query OK, 17736 rows affected (0.20 sec)
Records: 17736  Duplicates: 0  Warnings: 0



Session 1:

mysql> select connection_id();  
+-----------------+
| connection_id() |
+-----------------+
|               1 |
+-----------------+
1 row in set (0.00 sec)

mysql> select * from p300 where sn<20;
+----+------+-------------+
| sn | uuid | mobilePhone |
+----+------+-------------+
|  1 |    1 |         111 |
|  3 |    3 |        3333 |
|  5 |    5 |        5555 |
| 10 |   10 |         222 |
+----+------+-------------+
4 rows in set (0.00 sec)


mysql> start transaction;
Query OK, 0 rows affected (0.00 sec)

mysql> select * from p300 where uuid = 6 for update;
Empty set (0.00 sec)



Session 2:
mysql> select connection_id();
+-----------------+
| connection_id() |
+-----------------+
|               2 |
+-----------------+
1 row in set (0.00 sec)

mysql> start transaction;
Query OK, 0 rows affected (0.00 sec)

mysql> start transaction;
Query OK, 0 rows affected (0.00 sec)

mysql> insert into p300 values(1,1,1);
ERROR 1062 (23000): Duplicate entry '1' for key 'PRIMARY'
mysql> insert into p300(uuid,mobilePhone) values(1,1);
Query OK, 1 row affected (0.00 sec)

mysql> insert into p300(uuid,mobilePhone) values(2,1);
Query OK, 1 row affected (0.00 sec)

mysql> insert into p300(uuid,mobilePhone) values(3,1);
Query OK, 1 row affected (0.00 sec)

mysql> insert into p300(uuid,mobilePhone) values(4,1);
Query OK, 1 row affected (0.00 sec)

mysql> insert into p300(uuid,mobilePhone) values(5,1);
ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transaction
mysql> insert into p300(uuid,mobilePhone) values(6,1);
ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transaction
mysql> insert into p300(uuid,mobilePhone) values(7,1);
ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transaction
mysql> insert into p300(uuid,mobilePhone) values(8,1);
ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transaction
mysql> insert into p300(uuid,mobilePhone) values(9,1);
ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transaction
mysql> insert into p300(uuid,mobilePhone) values(10,1);
Query OK, 1 row affected (0.00 sec)

mysql> insert into p300(uuid,mobilePhone) values(11,1);
Query OK, 1 row affected (0.00 sec)



虽然select * from p300 where uuid = 6 for update; uud=6并不存在,但是还是锁了[5,10)




那么有值的情况 mysql 是怎么锁区间的呢?


Session 1:
mysql> select connection_id(); 
+-----------------+
| connection_id() |
+-----------------+
|               1 |
+-----------------+
1 row in set (0.00 sec)

mysql> select * from p300 where sn<20;
+----+------+-------------+
| sn | uuid | mobilePhone |
+----+------+-------------+
|  1 |    1 |         111 |
|  3 |    3 |        3333 |
|  5 |    5 |        5555 |
| 10 |   10 |         222 |
+----+------+-------------+
4 rows in set (0.00 sec)



mysql> start transaction;
Query OK, 0 rows affected (0.00 sec)

mysql>  select * from p300 where uuid =5 for update;
+----+------+-------------+
| sn | uuid | mobilePhone |
+----+------+-------------+
|  5 |    5 |        5555 |
+----+------+-------------+
1 row in set (0.00 sec)




Session 2:

mysql> select connection_id(); 
+-----------------+
| connection_id() |
+-----------------+
|               2 |
+-----------------+
1 row in set (0.00 sec)

mysql>  insert into p300(uuid,mobilePhone) values(1,1);
Query OK, 1 row affected (0.00 sec)

mysql>  insert into p300(uuid,mobilePhone) values(2,1);
Query OK, 1 row affected (0.00 sec)

mysql>  insert into p300(uuid,mobilePhone) values(3,1);
ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transaction
mysql>  insert into p300(uuid,mobilePhone) values(3,1);
ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transaction
mysql>  insert into p300(uuid,mobilePhone) values(4,1);
ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transaction
mysql>  insert into p300(uuid,mobilePhone) values(5,1);
ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transaction
mysql>  insert into p300(uuid,mobilePhone) values(6,1);
ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transaction
mysql>  insert into p300(uuid,mobilePhone) values(7,1);
ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transaction
mysql>  insert into p300(uuid,mobilePhone) values(8,1);
ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transaction
mysql>  insert into p300(uuid,mobilePhone) values(9,1);
ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transaction
mysql>  insert into p300(uuid,mobilePhone) values(10,1);
Query OK, 1 row affected (0.00 sec)

mysql>  insert into p300(uuid,mobilePhone) values(11,1);
Query OK, 1 row affected (0.00 sec)


select * from p300 where uuid =5 for update; 有值 此时锁住的区间是[5,10);