Mysql b\u锁定\u等待\u超时）。当你第二次戳事务1，而#2仍然需要一个锁时，InnoDB就放弃了
底线：与死锁共存。当它们发生时，从Mysql b\u锁定\u等待\u超时）。当你第二次戳事务1，而#2仍然需要一个锁时，InnoDB就放弃了,mysql,concurrency,transactions,locking,Mysql,Concurrency,Transactions,Locking,底线：与死锁共存。当它们发生时，从BEGIN开始。您还发现了另一个不明显的情况，即发生了不必要的死锁 此外，我怀疑修复此案例的代码会减慢大多数其他案例的速度，并导致一系列错误，这些错误需要几次发布才能发现和修复。我怀疑之所以会出现死锁，是因为InnoDB在处理“漏洞”方面比较保守。请注意，100和700都位于同一个未被触及的土地的模糊区域。InnoDB无法（或至少没有）处理“100”和“700”不同的事实。InnoDB希望标记单个行，但表中没有包含这些ID的行 事务2可能会超时（请参见innod
BEGIN此外，我怀疑修复此案例的代码会减慢大多数其他案例的速度，并导致一系列错误，这些错误需要几次发布才能发现和修复。我怀疑之所以会出现死锁，是因为InnoDB在处理“漏洞”方面比较保守。请注意，100和700都位于同一个未被触及的土地的模糊区域。InnoDB无法（或至少没有）处理“100”和“700”不同的事实。InnoDB希望标记单个行，但表中没有包含这些ID的行 事务2可能会超时（请参见
innodb\u lock\u wait\u timeoutBEGIN此外，我怀疑修复此案例的代码会减慢大多数其他案例的速度，并导致一系列错误，这些错误需要几次发布才能发现和修复。此死锁错误是MySQL InnoDB引擎中的一个缺陷，已12年未修复。（错误#25847:，解决方法：）它与唯一密钥无关。运行此查询还将导致相同的死锁错误
Session #1: CREATE TABLE t (id int) ENGINE=InnoDB;
Session #1: SET AUTOCOMMIT = 0;
Session #1: SELECT id FROM t WHERE id = 1 FOR UPDATE;
Session #2: SET AUTOCOMMIT = 0;
Session #2: SELECT id FROM t WHERE id = 2 FOR UPDATE;
Session #1: INSERT INTO t (id) VALUES (1); -- Hang
Session #2: INSERT INTO t (id) VALUES (2); -- Session #1: OK, Session #2: Deadlock found when trying to get lock; try restarting transaction
------------------------
LATEST DETECTED DEADLOCK
------------------------
2019-10-24 00:25:31 0x1638
*** (1) TRANSACTION:
TRANSACTION 1287, ACTIVE 62 sec inserting
mysql tables in use 1, locked 1
LOCK WAIT 3 lock struct(s), heap size 1136, 2 row lock(s)
MySQL thread id 7, OS thread handle 9444, query id 143 localhost ::1 root update
INSERT INTO t (id) VALUES (1)
*** (1) WAITING FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 23 page no 3 n bits 72 index GEN_CLUST_INDEX of table `test`.`t` trx id 1287 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; asc supremum;;
*** (2) TRANSACTION:
TRANSACTION 1288, ACTIVE 19 sec inserting, thread declared inside InnoDB 5000
mysql tables in use 1, locked 1
3 lock struct(s), heap size 1136, 2 row lock(s)
MySQL thread id 9, OS thread handle 5688, query id 145 localhost ::1 root update
INSERT INTO t (id) VALUES (2)
*** (2) HOLDS THE LOCK(S):
RECORD LOCKS space id 23 page no 3 n bits 72 index GEN_CLUST_INDEX of table `test`.`t` trx id 1288 lock_mode X
Record lock, heap no 1 PHYSICAL RECORD: n_fields 1; compact format; info bits 0
0: len 8; hex 73757072656d756d; asc supremum;;
*** (2) WAITING FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 23 page no 3 n bits 72 index GEN_CLUST_INDEX of table `test`.`t` trx id 1288 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; asc supremum;;
*** WE ROLL BACK TRANSACTION (2)
这个死锁错误是MySQL InnoDB引擎中的一个bug，已经12年没有修复了。（错误#25847:，解决方法：）它与唯一密钥无关。运行此查询还将导致相同的死锁错误
Session #1: CREATE TABLE t (id int) ENGINE=InnoDB;
Session #1: SET AUTOCOMMIT = 0;
Session #1: SELECT id FROM t WHERE id = 1 FOR UPDATE;
Session #2: SET AUTOCOMMIT = 0;
Session #2: SELECT id FROM t WHERE id = 2 FOR UPDATE;
Session #1: INSERT INTO t (id) VALUES (1); -- Hang
Session #2: INSERT INTO t (id) VALUES (2); -- Session #1: OK, Session #2: Deadlock found when trying to get lock; try restarting transaction
------------------------
LATEST DETECTED DEADLOCK
------------------------
2019-10-24 00:25:31 0x1638
*** (1) TRANSACTION:
TRANSACTION 1287, ACTIVE 62 sec inserting
mysql tables in use 1, locked 1
LOCK WAIT 3 lock struct(s), heap size 1136, 2 row lock(s)
MySQL thread id 7, OS thread handle 9444, query id 143 localhost ::1 root update
INSERT INTO t (id) VALUES (1)
*** (1) WAITING FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 23 page no 3 n bits 72 index GEN_CLUST_INDEX of table `test`.`t` trx id 1287 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; asc supremum;;
*** (2) TRANSACTION:
TRANSACTION 1288, ACTIVE 19 sec inserting, thread declared inside InnoDB 5000
mysql tables in use 1, locked 1
3 lock struct(s), heap size 1136, 2 row lock(s)
MySQL thread id 9, OS thread handle 5688, query id 145 localhost ::1 root update
INSERT INTO t (id) VALUES (2)
*** (2) HOLDS THE LOCK(S):
RECORD LOCKS space id 23 page no 3 n bits 72 index GEN_CLUST_INDEX of table `test`.`t` trx id 1288 lock_mode X
Record lock, heap no 1 PHYSICAL RECORD: n_fields 1; compact format; info bits 0
0: len 8; hex 73757072656d756d; asc supremum;;
*** (2) WAITING FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 23 page no 3 n bits 72 index GEN_CLUST_INDEX of table `test`.`t` trx id 1288 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; asc supremum;;
*** WE ROLL BACK TRANSACTION (2)
你想解决什么：）？这是不是很奇怪mysql为什么要这么做？或者您试图解决的是一个特定的问题吗？我试图解决我的应用程序中的死锁（当然表d不是真实的）。为了更清楚，在问题中添加了这个。您想解决什么：）？这是不是很奇怪mysql为什么要这么做？或者您试图解决的是一个特定的问题吗？我试图解决我的应用程序中的死锁（当然表d不是真实的）。将此添加到问题中以更清晰。谢谢。但是现在我在MySQL 5.7上测试了它，谢谢。但是现在我在MySQL 5.7上测试了它
insert into d values (700);
insert into d values (100); --> ERROR 1213 (40001): Deadlock found when trying to get lock; try restarting transaction in Session #1
insert into d values (700); --> Query OK, 1 row affected (4,08 sec) in Session #2
------------------------
LATEST DETECTED DEADLOCK
------------------------
2017-07-06 15:59:25 0x70000350d000
*** (1) TRANSACTION:
TRANSACTION 43567, ACTIVE 15 sec inserting
mysql tables in use 1, locked 1
LOCK WAIT 3 lock struct(s), heap size 1136, 2 row lock(s), undo log entries 1
MySQL thread id 4, OS thread handle 123145358217216, query id 89 localhost root update
insert into d values (700)
*** (1) WAITING FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 126 page no 4 n bits 72 index id of table `trx`.`d` trx id 43567 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; asc supremum;;
*** (2) TRANSACTION:
TRANSACTION 43568, ACTIVE 7 sec inserting
mysql tables in use 1, locked 1
3 lock struct(s), heap size 1136, 2 row lock(s), undo log entries 1
MySQL thread id 3, OS thread handle 123145357938688, query id 90 localhost root update
insert into d values (100)
*** (2) HOLDS THE LOCK(S):
RECORD LOCKS space id 126 page no 4 n bits 72 index id of table `trx`.`d` trx id 43568 lock_mode X
Record lock, heap no 1 PHYSICAL RECORD: n_fields 1; compact format; info bits 0
0: len 8; hex 73757072656d756d; asc supremum;;
*** (2) WAITING FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 126 page no 4 n bits 72 index id of table `trx`.`d` trx id 43568 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; asc supremum;;
*** WE ROLL BACK TRANSACTION (2)
mysql> select * from performance_schema.data_locks \G
*************************** 1. row ***************************
ENGINE: INNODB
ENGINE_LOCK_ID: 1808:76
ENGINE_TRANSACTION_ID: 1808
THREAD_ID: 35
EVENT_ID: 13081
OBJECT_SCHEMA: test
OBJECT_NAME: d
PARTITION_NAME: NULL
SUBPARTITION_NAME: NULL
INDEX_NAME: NULL
OBJECT_INSTANCE_BEGIN: 139756088373592
LOCK_TYPE: TABLE
LOCK_MODE: IX
LOCK_STATUS: GRANTED
LOCK_DATA: NULL
*************************** 2. row ***************************
ENGINE: INNODB
ENGINE_LOCK_ID: 1808:2:5:1
ENGINE_TRANSACTION_ID: 1808
THREAD_ID: 35
EVENT_ID: 13111
OBJECT_SCHEMA: test
OBJECT_NAME: d
PARTITION_NAME: NULL
SUBPARTITION_NAME: NULL
INDEX_NAME: id
OBJECT_INSTANCE_BEGIN: 139756088370552
LOCK_TYPE: RECORD
LOCK_MODE: X
LOCK_STATUS: GRANTED
LOCK_DATA: supremum pseudo-record <--- HERE
2 rows in set (0.00 sec)
Session #1: CREATE TABLE t (id int) ENGINE=InnoDB;
Session #1: SET AUTOCOMMIT = 0;
Session #1: SELECT id FROM t WHERE id = 1 FOR UPDATE;
Session #2: SET AUTOCOMMIT = 0;
Session #2: SELECT id FROM t WHERE id = 2 FOR UPDATE;
Session #1: INSERT INTO t (id) VALUES (1); -- Hang
Session #2: INSERT INTO t (id) VALUES (2); -- Session #1: OK, Session #2: Deadlock found when trying to get lock; try restarting transaction
------------------------
LATEST DETECTED DEADLOCK
------------------------
2019-10-24 00:25:31 0x1638
*** (1) TRANSACTION:
TRANSACTION 1287, ACTIVE 62 sec inserting
mysql tables in use 1, locked 1
LOCK WAIT 3 lock struct(s), heap size 1136, 2 row lock(s)
MySQL thread id 7, OS thread handle 9444, query id 143 localhost ::1 root update
INSERT INTO t (id) VALUES (1)
*** (1) WAITING FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 23 page no 3 n bits 72 index GEN_CLUST_INDEX of table `test`.`t` trx id 1287 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; asc supremum;;
*** (2) TRANSACTION:
TRANSACTION 1288, ACTIVE 19 sec inserting, thread declared inside InnoDB 5000
mysql tables in use 1, locked 1
3 lock struct(s), heap size 1136, 2 row lock(s)
MySQL thread id 9, OS thread handle 5688, query id 145 localhost ::1 root update
INSERT INTO t (id) VALUES (2)
*** (2) HOLDS THE LOCK(S):
RECORD LOCKS space id 23 page no 3 n bits 72 index GEN_CLUST_INDEX of table `test`.`t` trx id 1288 lock_mode X
Record lock, heap no 1 PHYSICAL RECORD: n_fields 1; compact format; info bits 0
0: len 8; hex 73757072656d756d; asc supremum;;
*** (2) WAITING FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 23 page no 3 n bits 72 index GEN_CLUST_INDEX of table `test`.`t` trx id 1288 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; asc supremum;;
*** WE ROLL BACK TRANSACTION (2)