mysql 事物 锁行 测试_MySQL Transaction--RR事务隔离级别下加锁测试
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按照非索引列更新
在可重復讀的事務隔離級別下，在非索引列上進行更新和刪除會對所有數據行進行加鎖，阻止其他會話對邊進行任何數據的增刪改操作。
如果更新或刪除條件為c3=4且c3列上沒有索引則：1、不允許其他會話插入任意記錄，因為所有記錄的主鍵索引上存在X排他鎖，無法申請插入意向X鎖(lock_mode X insertintention waiting Record lock)2、不允許其他會話刪除任意記錄，因為所有記錄的主鍵索引上存在X排他鎖3、不允許其他會話更新任意記錄。因為所有記錄的主鍵索引上存在X排他鎖
##=========================================##
測試數據：CREATE TABLE`tb4001` (
`id`bigint(20) NOT NULLAUTO_INCREMENT,
`c1`int(11) DEFAULT NULL,
`c2`varchar(200) DEFAULT NULL,
`c3`int(11) DEFAULT NULL,PRIMARY KEY(`id`),KEY`idx_c1` (`c1`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;insert into tb4001(c1,c2,c3) values(2,2,2);insert into tb4001(c1,c2,c3) values(4,4,4);insert into tb4001(c1,c2,c3) values(7,7,7);insert into tb4001(c1,c2,c3) values(8,8,8);
##=========================================##
##測試1：在沒有索引的列上更新
##事務隔離級別：RR
會話1：SET SESSION tx_isolation='REPEATABLE-READ';
STARTTRANSACTION;SELECT @@GLOBAL.tx_isolation, @@SESSION.tx_isolation;update tb4001 set c2=777 where c3=7;
##=========================================##
會話2:SET SESSION tx_isolation='REPEATABLE-READ';
STARTTRANSACTION;SELECT @@GLOBAL.tx_isolation, @@SESSION.tx_isolation;insert into tb4001(c1,c2,c3) values(9,9,9);
##執行結果：會話2被阻塞
使用SHOW ENGINE INNODB STATUS \G查看阻塞發生時的鎖信息------- TRX HAS BEEN WAITING 13 SEC FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 75 page no 3 n bits 80 index PRIMARY of table `test1`.`tb4001` trx id 10573 lock_mode X insert intention waiting Record lock, heap no 1 PHYSICAL RECORD: n_fields 1; compact format; info bits 0
0: len 8; hex 73757072656d756d; ascsupremum;;---------------------TRANSACTION 10571, ACTIVE 404 sec
2 lock struct(s), heap size 1136, 5 row lock(s), undo log entries 1MySQL thread id52, OS thread handle 140674621650688, query id 1201 127.0.0.1admin
##=========================================##
會話2:SET SESSION tx_isolation='REPEATABLE-READ';
STARTTRANSACTION;SELECT @@GLOBAL.tx_isolation, @@SESSION.tx_isolation;update tb4001 set c2=888 where c3=8;
##執行結果：會話2被阻塞
使用SHOW ENGINE INNODB STATUS \G查看阻塞發生時的鎖信息------- TRX HAS BEEN WAITING 5 SEC FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 75 page no 3 n bits 80 index PRIMARY of table `test1`.`tb4001` trx id 10573lock_mode X waiting
Record lock, heap no2 PHYSICAL RECORD: n_fields 6; compact format; info bits 0
0: len 8; hex 8000000000000001; asc;;1: len 6; hex 00000000293c; asc )
2 lock struct(s), heap size 1136, 5 row lock(s), undo log entries 1MySQL thread id52, OS thread handle 140674621650688, query id 1201 127.0.0.1admin
##=========================================##
會話2:SET SESSION tx_isolation='REPEATABLE-READ';
STARTTRANSACTION;SELECT @@GLOBAL.tx_isolation, @@SESSION.tx_isolation;delete from tb4001 where c3=8;
##執行結果：會話2被阻塞
使用SHOW ENGINE INNODB STATUS \G查看阻塞發生時的鎖信息------- TRX HAS BEEN WAITING 4 SEC FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 75 page no 3 n bits 80 index PRIMARY of table `test1`.`tb4001` trx id 10573lock_mode X waiting
Record lock, heap no2 PHYSICAL RECORD: n_fields 6; compact format; info bits 0
0: len 8; hex 8000000000000001; asc;;1: len 6; hex 00000000293c; asc )
2 lock struct(s), heap size 1136, 5 row lock(s), undo log entries 1MySQL thread id52, OS thread handle 140674621650688, query id 1201 127.0.0.1 admin
View Code
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按照非唯一索引更新
在可重復讀的事務隔離級別下，按照非主鍵非唯一索引進行更新和刪除，會對滿足條件的行加行鎖+滿足條件的區域加gap鎖
如果更新或刪除條件為c1=4且c1列上有非唯一索引則：1、允許其他會話插入c1<>4的記錄，但不允許插入c1=4的記錄2、允許其他會話更新c1<>4的記錄，但不允許將記錄更新為c1=4的記錄3、允許其他會話刪除c1<>4的記錄。4、允許插入\刪除\修改在c1列索引上與c1=4相鄰的記錄，雖然操作會影響gap鎖的邊界值。
##=========================================##
測試數據：CREATE TABLE`tb4001` (
`id`bigint(20) NOT NULLAUTO_INCREMENT,
`c1`int(11) DEFAULT NULL,
`c2`varchar(200) DEFAULT NULL,
`c3`int(11) DEFAULT NULL,PRIMARY KEY(`id`),KEY`idx_c1` (`c1`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;insert into tb4001(c1,c2,c3) values(2,2,2);insert into tb4001(c1,c2,c3) values(4,4,4);insert into tb4001(c1,c2,c3) values(7,7,7);insert into tb4001(c1,c2,c3) values(8,8,8);
##=========================================##
##測試1：在沒有索引的列上更新
##事務隔離級別：RR
會話1：SET SESSION tx_isolation='REPEATABLE-READ';
STARTTRANSACTION;SELECT @@GLOBAL.tx_isolation, @@SESSION.tx_isolation;update tb4001 set c2=777 where c1=7;
##=========================================##
會話2:begin;SET SESSION tx_isolation='REPEATABLE-READ';
STARTTRANSACTION;SELECT @@GLOBAL.tx_isolation, @@SESSION.tx_isolation;insert into tb4001(c1,c2,c3) values(9,9,9);
會話2未被阻塞成功執行
##=========================================##
會話2:SET SESSION tx_isolation='REPEATABLE-READ';
STARTTRANSACTION;SELECT @@GLOBAL.tx_isolation, @@SESSION.tx_isolation;insert into tb4001(c1,c2,c3) values(7,7,7);
##執行結果：會話2被阻塞
使用SHOW ENGINE INNODB STATUS \G查看阻塞發生時的鎖信息---TRANSACTION 10600, ACTIVE 7 sec inserting
mysql tables in use 1, locked 1LOCK WAIT2 lock struct(s), heap size 1136, 1 row lock(s), undo log entries 1MySQL thread id53, OS thread handle 140674620851968, query id 1317 127.0.0.1 admin update
insert into tb4001(c1,c2,c3) values(7,7,7)------- TRX HAS BEEN WAITING 7 SEC FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 75 page no 4 n bits 72 index idx_c1 of table `test1`.`tb4001` trx id 10600 lock_mode X locks gap before rec insertintention waiting
Record lock, heap no5 PHYSICAL RECORD: n_fields 2; compact format; info bits 0
0: len 4; hex 80000008; asc;;1: len 8; hex 8000000000000004; asc;;---------------------TRANSACTION 10598, ACTIVE 270 sec
4 lock struct(s), heap size 1136, 3 row lock(s), undo log entries 1MySQL thread id52, OS thread handle 140674621650688, query id 1306 127.0.0.1admin
##=========================================##
會話2:SET SESSION tx_isolation='REPEATABLE-READ';
STARTTRANSACTION;SELECT @@GLOBAL.tx_isolation, @@SESSION.tx_isolation;delete from tb4001 where c1=8;
會話2未被阻塞成功執行
##=========================================##
會話2:SET SESSION tx_isolation='REPEATABLE-READ';
STARTTRANSACTION;SELECT @@GLOBAL.tx_isolation, @@SESSION.tx_isolation;update tb4001 set c2=888 where c1=8;
會話2未被阻塞成功執行
##=========================================##
會話2:SET SESSION tx_isolation='REPEATABLE-READ';
STARTTRANSACTION;SELECT @@GLOBAL.tx_isolation, @@SESSION.tx_isolation;delete from tb4001 where c1=4;
會話2未被阻塞成功執行
##=========================================##
View Code
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按照非唯一索引+條件更新
在可重復讀事務隔離級別下，按照對非唯一索引列進行更新，會對掃描到的所有索引記錄進行更新，無論該記錄是否滿足WHERE中的其他條件。
##=========================================##
測試數據：CREATE TABLE`tb4001` (
`id`bigint(20) NOT NULLAUTO_INCREMENT,
`c1`int(11) DEFAULT NULL,
`c2`varchar(200) DEFAULT NULL,
`c3`int(11) DEFAULT NULL,PRIMARY KEY(`id`),KEY`idx_c1` (`c1`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;insert into tb4001(c1,c2,c3) values(2,2,2);insert into tb4001(c1,c2,c3) values(4,4,4);insert into tb4001(c1,c2,c3) values(4,4,44);insert into tb4001(c1,c2,c3) values(7,7,7);insert into tb4001(c1,c2,c3) values(8,8,8);
##=========================================##
##會話1：
##事務隔離級別：RR
會話1：SET SESSION tx_isolation='REPEATABLE-READ';
STARTTRANSACTION;SELECT @@GLOBAL.tx_isolation, @@SESSION.tx_isolation;update tb4001 set c2=444 where c1=4 and c3=4;
##=========================================##
##會話2：SET SESSION tx_isolation='REPEATABLE-READ';
STARTTRANSACTION;SELECT @@GLOBAL.tx_isolation, @@SESSION.tx_isolation;update tb4001 set c2=444 where c1=4 and c3=44;
會話2未被阻塞成功執行
##執行結果：會話2被阻塞
mysql tablesin use 1, locked 1LOCK WAIT2 lock struct(s), heap size 1136, 1row lock(s)
MySQL thread id76, OS thread handle 140674621384448, query id 1636 127.0.0.1admin updatingupdate tb4001 set c2=444 where c1=4 and c3=44
------- TRX HAS BEEN WAITING 13 SEC FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 79 page no 4 n bits 72 index idx_c1 of table `test1`.`tb4001` trx id 10781lock_mode X waiting
Record lock, heap no3 PHYSICAL RECORD: n_fields 2; compact format; info bits 0
0: len 4; hex 80000004; asc;;1: len 8; hex 8000000000000002; asc;;---------------------TRANSACTION 10780, ACTIVE 52 sec
4 lock struct(s), heap size 1136, 5 row lock(s), undo log entries 1MySQL thread id75, OS thread handle 140674621916928, query id 1618 127.0.0.1admin
##=========================================##
View Code
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按照非唯一組合索引更新
假設表TB1上有列C1和C2，有索引IDC_C1_C2(C1,C2)
在可重復提交事務隔離級別下,會話1按照C1=3 AND C2=4進行更新，則：1、會話2按照C1=3 AND C2=4進行更新,更新操作被阻塞2、會話2按照C1=3 AND C2=M(M<>4)進行更新,更新操作不會被阻塞3、會話2可以在C1=3 AND C2=4之后間隙插入記錄，但不能在C1=3 AND C2=4之前的間隙插入記錄
##=========================================##
##測試數據CREATE TABLE`tb4001` (
`id`bigint(20) NOT NULLAUTO_INCREMENT,
`c1`int(11) DEFAULT NULL,
`c2`varchar(200) DEFAULT NULL,
`c3`int(11) DEFAULT NULL,PRIMARY KEY(`id`),KEY`idx_c1_c3` (`c1`,`c3`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;insert into tb4001(c1,c2,c3) values(2,2,2);insert into tb4001(c1,c2,c3) values(4,4,4);insert into tb4001(c1,c2,c3) values(4,4,44);insert into tb4001(c1,c2,c3) values(7,7,7);insert into tb4001(c1,c2,c3) values(8,8,8);
##=========================================##
##會話1：
##事務隔離級別：RR
會話1：SET SESSION tx_isolation='REPEATABLE-READ';
STARTTRANSACTION;SELECT @@GLOBAL.tx_isolation, @@SESSION.tx_isolation;update tb4001 set c2=444 where c1=4 and c3=4;
##=========================================##
##會話2：SET SESSION tx_isolation='REPEATABLE-READ';
STARTTRANSACTION;SELECT @@GLOBAL.tx_isolation, @@SESSION.tx_isolation;update tb4001 set c2=444 where c1=4 and c3=44;
會話2未被阻塞成功執行
##=========================================##
##會話2：SET SESSION tx_isolation='REPEATABLE-READ';
STARTTRANSACTION;SELECT @@GLOBAL.tx_isolation, @@SESSION.tx_isolation;update tb4001 set c2=444 where c1=2 and c3=2;
會話2未被阻塞成功執行
##=========================================##
##會話2：SET SESSION tx_isolation='REPEATABLE-READ';
STARTTRANSACTION;SELECT @@GLOBAL.tx_isolation, @@SESSION.tx_isolation;insert into tb4001(c1,c2,c3) values(4,4,3);
會話2被阻塞
##=========================================##
View Code
==============================================================================
按照唯一索引進行更新
在可重復讀的事務隔離級別下，在唯一索引列上進行更新和刪除在唯一索引的索引行上加排他鎖。
如果更新或刪除條件為c1=7且c1列上存在唯一索引則：1、阻止其他會話刪除和修改c1=7的記錄2、阻止其他會話插入c1=7的記錄3、允許其他會話插入\刪除\修改c1<>7的記錄，但不允許將記錄修改為c1=7的記錄
以上限制通過在唯一索引的索引記錄上加排他鎖X來實現，不會生產GAP鎖
在根據唯一索引進行更新時，讀提交事務隔離級別(RC)和可重復讀事務隔離級別(RR)都只需要依賴唯一索引便可以保證事務ACID特性，無須使用GAP鎖。
##=========================================##
測試數據：CREATE TABLE`tb4001` (
`id`bigint(20) NOT NULLAUTO_INCREMENT,
`c1`int(11) DEFAULT NULL,
`c2`varchar(200) DEFAULT NULL,
`c3`int(11) DEFAULT NULL,PRIMARY KEY(`id`),UNIQUE KEY`idx_c1` (`c1`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;insert into tb4001(c1,c2,c3) values(2,2,2);insert into tb4001(c1,c2,c3) values(4,4,4);insert into tb4001(c1,c2,c3) values(7,7,7);insert into tb4001(c1,c2,c3) values(8,8,8);
##=========================================##
##測試1：在沒有索引的列上更新
##事務隔離級別：RR
會話1：SET SESSION tx_isolation='REPEATABLE-READ';
STARTTRANSACTION;SELECT @@GLOBAL.tx_isolation, @@SESSION.tx_isolation;update tb4001 set c2=777 where c1=7;
##=========================================##
會話2：SET SESSION tx_isolation='REPEATABLE-READ';
STARTTRANSACTION;SELECT @@GLOBAL.tx_isolation, @@SESSION.tx_isolation;insert into tb4001(c1,c2,c3) values(6,6,6);
會話2未被阻塞成功執行
##=========================================##
會話2：SET SESSION tx_isolation='REPEATABLE-READ';
STARTTRANSACTION;SELECT @@GLOBAL.tx_isolation, @@SESSION.tx_isolation;insert into tb4001(c1,c2,c3) values(7,7,7);
##執行結果：會話2被阻塞
使用SHOW ENGINE INNODB STATUS \G查看阻塞發生時的鎖信息---TRANSACTION 10727, ACTIVE 9 sec inserting
mysql tables in use 1, locked 1LOCK WAIT2 lock struct(s), heap size 1136, 1 row lock(s), undo log entries 1MySQL thread id53, OS thread handle 140674620851968, query id 1553 127.0.0.1 admin update
insert into tb4001(c1,c2,c3) values(7,7,7)------- TRX HAS BEEN WAITING 9 SEC FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 77 page no 4 n bits 72 index idx_c1 of table `test1`.`tb4001` trx id 10727lock mode S waiting
Record lock, heap no4 PHYSICAL RECORD: n_fields 2; compact format; info bits 0
0: len 4; hex 80000007; asc;;1: len 8; hex 8000000000000003; asc;;---------------------TRANSACTION 10721, ACTIVE 32 sec
3 lock struct(s), heap size 1136, 2 row lock(s), undo log entries 1MySQL thread id52, OS thread handle 140674621650688, query id 1544 127.0.0.1admin
##=========================================##
會話2：SET SESSION tx_isolation='REPEATABLE-READ';
STARTTRANSACTION;SELECT @@GLOBAL.tx_isolation, @@SESSION.tx_isolation;update tb4001 set c2=888 where c1=8;
會話2未被阻塞成功執行
##=========================================##
會話2：SET SESSION tx_isolation='REPEATABLE-READ';
STARTTRANSACTION;SELECT @@GLOBAL.tx_isolation, @@SESSION.tx_isolation;update tb4001 set c1=7 where c1=8;
會話2未被阻塞成功執行
##執行結果：會話2被阻塞
使用SHOW ENGINE INNODB STATUS \G查看阻塞發生時的鎖信息---TRANSACTION 10730, ACTIVE 4 sec updating or deleting
mysql tables in use 1, locked 1LOCK WAIT4 lock struct(s), heap size 1136, 3 row lock(s), undo log entries 1MySQL thread id53, OS thread handle 140674620851968, query id 1567 127.0.0.1admin updatingupdate tb4001 set c1=7 where c1=8
------- TRX HAS BEEN WAITING 4 SEC FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 77 page no 4 n bits 72 index idx_c1 of table `test1`.`tb4001` trx id 10730lock mode S waiting
Record lock, heap no4 PHYSICAL RECORD: n_fields 2; compact format; info bits 0
0: len 4; hex 80000007; asc;;1: len 8; hex 8000000000000003; asc;;---------------------TRANSACTION 10721, ACTIVE 100 sec
3 lock struct(s), heap size 1136, 2 row lock(s), undo log entries 1MySQL thread id52, OS thread handle 140674621650688, query id 1544 127.0.0.1admin
##=========================================##
會話2：SET SESSION tx_isolation='REPEATABLE-READ';
STARTTRANSACTION;SELECT @@GLOBAL.tx_isolation, @@SESSION.tx_isolation;delete from tb4001 where c1=8;
會話2未被阻塞成功執行
View Code
==============================================================================
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