Deadlock found when trying to get lock; try restarting transaction解决方式
MySQL 事务的学习整理：[url]http://blog.csdn.net/mchdba/article/details/12242685[/url]
mysql事务处理用法与实例详解：[url]http://www.cnblogs.com/ymy124/p/3718439.html[/url]
常见的表死锁情况及解决方法：[url]http://www.cnblogs.com/jeffry/p/6014881.html[/url]
MySQL事务autocommit自动提交：[url]http://www.qttc.net/201208175.html[/url]
MySql 死锁时的一种解决办法：[url]http://www.cnblogs.com/farb/p/MySqlDeadLockOneOfSolutions.html[/url]
Mysql并发时经典常见的死锁原因及解决方法:[url]http://www.cnblogs.com/zejin2008/p/5262751.html[/url]
mysql死锁几种情况的测试：[url]http://www.2cto.com/database/201605/507289.html[/url]，
[url]http://blog.csdn.net/aoerqileng/article/details/51354357[/url]
Mysql中那些锁机制之InnoDB：[url]http://www.2cto.com/database/201508/429967.html[/url]
InnoDB Record, Gap, and Next-Key Locks:[url]http://www.cnblogs.com/zemliu/p/3503496.html[/url]
[b]准备工作：[/b]
建表，初始化数据，
[b]模拟死锁：[/b]
开启会话A,开启一个事务
Session A:
开启会话B,删除用户id为1的用户
回到会话A,删除用户id为1的用户
[b]0.查看MySQL当前连接线程:[/b]
mysql>
[b]1.查看引擎日志分析死锁的原因：[/b]
查看死锁信息
[b]2.查看Mysql事务:[/b]
2.a 查看当前事务：
2.b 查看当前锁定的事务
2.c 查看当前等锁的事务
找出死锁关联的事务线程id（trx_mysql_thread_id），从上面的分析得出，持有锁的MySQL事务线程id为1020088
[b]3.Kill 关联事务线程[/b]
[b]4.再次查看当前等待锁的事务及当前事务：[/b]
在分析之前先来看一下MySQL的锁机制，MySQLl锁机制有行级锁和表级锁,
InnoDB实现了两种类型的行锁:
共享锁（S）：允许一个事务去读一行，阻止其他事务获得相同的数据集的排他锁。
排他锁（X）：允许获得排他锁的事务更新数据，但是组织其他事务获得相同数据集的共享锁和排他锁。
共享锁就是我读的时候，你可以读，但是不能写。排他锁就是我写的时候，你不能读也不能写。其实就是MyISAM的读锁和写锁，但是针对的对象不同了而已。
除此之外InnoDB还有两个表锁：
意向共享锁（IS）：表示事务准备给数据行加入共享锁，也就是说一个数据行加共享锁前必须先取得该表的IS锁
意向排他锁（IX）：类似上面，表示事务准备给数据行加入排他锁，说明事务在一个数据行加排他锁前必须先取得该表的IX锁。
InnoDB行锁模式兼容列表，见下这篇文章
InnoDB的行锁模式及加锁方法：[url]http://lib.csdn.net/article/mysql/8747[/url]
[color=red][b]注意：[/b][/color]
当一个事务请求的锁模式与当前的锁兼容，InnoDB就将请求的锁授予该事务；反之如果请求不兼容，则该事务就等待锁释放。意向锁是InnoDB自动加的，不需要用户干预。
对于insert、update、delete，InnoDB会自动给涉及的数据加排他锁（X）；
对于一般的Select语句，InnoDB不会加任何锁，事务可以通过以下语句给显示加共享锁或排他锁。
共享锁：select * from table_name where .....lock in share mode
排他锁：select * from table_name where .....for update
[b]分析死锁原因:[/b]
出现死锁的原因，是因为会话A开启一个事务，以共享锁S锁，获取user表id为1的一行记录；
会话B，删除user表id为1记录，请求排他锁X锁，由于SX锁互斥，会话B等待会话A释放共享锁S锁，进入请求队列等待；这时，会话A删除user表id为1记录,请求排他锁X锁，但会话B在请求队列中，还轮不到会话A，会话A就等待，这种循环等待出现，死锁就出现了。
附：
这部分与上面无关，只作为记录
检查数据库表状态：
mysql>
检查指定表状态：
如果表状态不OK，则修复：
查看数据库当前事务提交状态：
查看数据库事务隔离级别：
MySQL的线程状态快照：
快照1：
快照2：
mysql事务处理用法与实例详解：[url]http://www.cnblogs.com/ymy124/p/3718439.html[/url]
常见的表死锁情况及解决方法：[url]http://www.cnblogs.com/jeffry/p/6014881.html[/url]
MySQL事务autocommit自动提交：[url]http://www.qttc.net/201208175.html[/url]
MySql 死锁时的一种解决办法：[url]http://www.cnblogs.com/farb/p/MySqlDeadLockOneOfSolutions.html[/url]
Mysql并发时经典常见的死锁原因及解决方法:[url]http://www.cnblogs.com/zejin2008/p/5262751.html[/url]
mysql死锁几种情况的测试：[url]http://www.2cto.com/database/201605/507289.html[/url]，
[url]http://blog.csdn.net/aoerqileng/article/details/51354357[/url]
Mysql中那些锁机制之InnoDB：[url]http://www.2cto.com/database/201508/429967.html[/url]
InnoDB Record, Gap, and Next-Key Locks:[url]http://www.cnblogs.com/zemliu/p/3503496.html[/url]
[b]准备工作：[/b]
建表，初始化数据，
SET FOREIGN_KEY_CHECKS=0;
-- ----------------------------
-- Table structure for user
-- ----------------------------
DROP TABLE IF EXISTS `user`;
CREATE TABLE `user` (
`id` int(11) NOT NULL auto_increment COMMENT 'id',
`name` varchar(10) default NULL,
`age` int(11) default NULL,
`registerTime` timestamp NULL default NULL on update CURRENT_TIMESTAMP,
PRIMARY KEY (`id`),
KEY `name` (`name`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
-- ----------------------------
-- Records of user
-- ----------------------------
INSERT INTO `user` VALUES ('1', 'jack', '23', null);
INSERT INTO `user` VALUES ('2', 'mark', '67', null);
INSERT INTO `user` VALUES ('3', 'donald', null, '2017-06-13 16:23:23');
[b]模拟死锁：[/b]
开启会话A,开启一个事务
Session A:
mysql> begin;
Query OK, 0 rows affected
mysql> select * from user where id=1 lock in share mode;;
+----+------+-----+--------------+
| id | name | age | registerTime |
+----+------+-----+--------------+
| 1 | jack | 23 | NULL |
+----+------+-----+--------------+
1 row in set开启会话B,删除用户id为1的用户
Session B：
mysql> delete from user where id = 1;回到会话A,删除用户id为1的用户
Session A：
mysql> mysql> delete from user where id = 1;
1213 - Deadlock found when trying to get lock; try restarting transaction[b]0.查看MySQL当前连接线程:[/b]
mysql> show processlist;
+---------+-----------------+-------------------+------+---------+---------+------------------------+------------------------------+
| Id | User | Host | db | Command | Time | State | Info |
+---------+-----------------+-------------------+------+---------+---------+------------------------+------------------------------+
| 1 | event_scheduler | localhost | NULL | Daemon | 3031152 | Waiting on empty queue | NULL |
| 1019932 | donald | 192.168.31.153:15217 | NULL | Sleep | 1872 | | NULL |
| 1019933 | donald | 192.168.31.153:15218 | test | Sleep | 188 | | NULL |
| 1020542 | donald | 192.168.31.153:16735 | test | Sleep | 179 | | NULL |
| 1020543 | donald | 192.168.31.153:16748 | test | Sleep | 14 | | NULL |
| 1020544 | donald | 192.168.31.153:16751 | test | Query | 72 | updating | delete from user where id =1 |
| 1020545 | donald | 192.168.31.153:16753 | test | Query | 0 | init | show processlist |
+---------+-----------------+-------------------+------+---------+---------+------------------------+------------------------------+
7 rows in setmysql>
[b]1.查看引擎日志分析死锁的原因：[/b]
show engine innodb status\G;查看死锁信息
| InnoDB | |
=====================================
2017-07-18 18:25:02 650ceb70 INNODB MONITOR OUTPUT
=====================================
Per second averages calculated from the last 6 seconds
-----------------
BACKGROUND THREAD 后台线程
-----------------
srv_master_thread loops: 530 srv_active, 0 srv_shutdown, 3056084 srv_idle
srv_master_thread log flush and writes: 3027072
----------
SEMAPHORES 信号量
----------
OS WAIT ARRAY INFO: reservation count 1059
OS WAIT ARRAY INFO: signal count 1047
Mutex spin waits 1035, rounds 8167, OS waits 165
RW-shared spins 870, rounds 26073, OS waits 867
RW-excl spins 33, rounds 1021, OS waits 25
Spin rounds per wait: 7.89 mutex, 29.97 RW-shared, 30.94 RW-excl
------------------------
LATEST DETECTED DEADLOCK 上次探测到死锁的状态
------------------------
2017-07-18 18:16:22 698d9b70
*** (1) TRANSACTION:事务1035410，MySQL事务线程1020087
TRANSACTION 1035410, ACTIVE 73 sec starting index read
mysql tables in use 1, locked 1
LOCK WAIT 2 lock struct(s), heap size 312, 1 row lock(s)
MySQL thread id 1020087, OS thread handle 0x69879b70, query id 195420 192.168.31.153 donald updating
delete from user where id = 1
*** (1) WAITING FOR THIS LOCK TO BE GRANTED:等待锁行级锁RECORD LOCKS，X锁，
RECORD LOCKS space id 7405 page no 3 n bits 72 index `PRIMARY` of table `test`.`user`
trx id 1035410 lock_mode X locks rec but not gap waiting
Record lock, heap no 2 PHYSICAL RECORD: n_fields 6; compact format; info bits 32
0: len 4; hex 80000001; asc ;;
1: len 6; hex 0000000fcc91; asc ;;
2: len 7; hex 68000080210a23; asc h ! #;;
3: len 4; hex 6a61636b; asc jack;;
4: len 4; hex 80000017; asc ;;
5: SQL NULL;
*** (2) TRANSACTION:事务1035409，MySQL事务线程1020088
TRANSACTION 1035409, ACTIVE 107 sec starting index read
mysql tables in use 1, locked 1
3 lock struct(s), heap size 312, 2 row lock(s), undo log entries 1
MySQL thread id 1020088, OS thread handle 0x698d9b70, query id 195422 192.168.31.153 donald Sending data
select * from user where id =1 lock in share mode
*** (2) HOLDS THE LOCK(S):当前事务持有锁，S锁，
RECORD LOCKS space id 7405 page no 3 n bits 72 index `PRIMARY` of table `test`.`user`
trx id 1035409 lock_mode X locks rec but not gapRecord lock, 非gap锁
heap no 2 PHYSICAL RECORD: n_fields 6; compact format; info bits 32
0: len 4; hex 80000001; asc ;;
1: len 6; hex 0000000fcc91; asc ;;
2: len 7; hex 68000080210a23; asc h ! #;;
3: len 4; hex 6a61636b; asc jack;;
4: len 4; hex 80000017; asc ;;
5: SQL NULL;
*** (2) WAITING FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 7405 page no 3 n bits 72 index `PRIMARY` of table `test`.`user`
trx id 1035409 lock mode S waiting Record lock, heap no 2 PHYSICAL RECORD:
n_fields 6; compact format; info bits 32
0: len 4; hex 80000001; asc ;;
1: len 6; hex 0000000fcc91; asc ;;
2: len 7; hex 68000080210a23; asc h ! #;;
3: len 4; hex 6a61636b; asc jack;;
4: len 4; hex 80000017; asc ;;
5: SQL NULL;
*** WE ROLL BACK TRANSACTION (1)
------------
TRANSACTIONS 回滚事务1035425
------------
Trx id counter 1035425
Purge done for trx's n:o < 1035408 undo n:o < 0 state: running but idle
History list length 1046
LIST OF TRANSACTIONS FOR EACH SESSION:每个会话的事务
---TRANSACTION 0, not started，
MySQL thread id 1020076, OS thread handle 0x650ceb70, query id 195466 192.168.31.153 donald init
show engine innodb status
---TRANSACTION 1035423, not started
MySQL thread id 1020089, OS thread handle 0x6503bb70, query id 195454 192.168.31.153 donald cleaning up
---TRANSACTION 1035424, not started
MySQL thread id 1020087, OS thread handle 0x69879b70, query id 195455 192.168.31.153 donald cleaning up
---TRANSACTION 0, not started
MySQL thread id 1019933, OS thread handle 0x6506cb70, query id 195428 192.168.31.153 donald cleaning up
---TRANSACTION 1035409, ACTIVE 627 sec 事务1035409，激活状态，MySQL线程id，1020088
3 lock struct(s), heap size 312, 5 row lock(s), undo log entries 1
MySQL thread id 1020088, OS thread handle 0x698d9b70, query id 195456 192.168.31.153 donald cleaning up
--------
FILE I/O
--------
I/O thread 0 state: waiting for completed aio requests (insert buffer thread)
I/O thread 1 state: waiting for completed aio requests (log thread)
I/O thread 2 state: waiting for completed aio requests (read thread)
I/O thread 3 state: waiting for completed aio requests (read thread)
I/O thread 4 state: waiting for completed aio requests (read thread)
I/O thread 5 state: waiting for completed aio requests (read thread)
I/O thread 6 state: waiting for completed aio requests (write thread)
I/O thread 7 state: waiting for completed aio requests (write thread)
I/O thread 8 state: waiting for completed aio requests (write thread)
I/O thread 9 state: waiting for completed aio requests (write thread)
Pending normal aio reads: 0 [0, 0, 0, 0] , aio writes: 0 [0, 0, 0, 0] ,
ibuf aio reads: 0, log i/o's: 0, sync i/o's: 0
Pending flushes (fsync) log: 0; buffer pool: 0
3034 OS file reads, 46735 OS file writes, 12238 OS fsyncs
0.00 reads/s, 0 avg bytes/read, 0.00 writes/s, 0.00 fsyncs/s
-------------------------------------
INSERT BUFFER AND ADAPTIVE HASH INDEX
-------------------------------------
Ibuf: size 1, free list len 26781, seg size 26783, 0 merges
merged operations:
insert 0, delete mark 0, delete 0
discarded operations:
insert 0, delete mark 0, delete 0
Hash table size 9239933, node heap has 24 buffer(s)
0.00 hash searches/s, 0.00 non-hash searches/s
---
LOG
---
Log sequence number 709253455618
Log flushed up to 709253455618
Pages flushed up to 709253455618
Last checkpoint at 709253455618
0 pending log writes, 0 pending chkp writes
3279 log i/o's done, 0.00 log i/o's/second
----------------------
BUFFER POOL AND MEMORY
----------------------
Total memory allocated 2136604672; in additional pool allocated 0
Dictionary memory allocated 745414
Buffer pool size 128000
Free buffers 93253
Database pages 34723
Old database pages 12657
Modified db pages 0
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 1, not young 0
0.00 youngs/s, 0.00 non-youngs/s
Pages read 2779, created 31944, written 37451
0.00 reads/s, 0.00 creates/s, 0.00 writes/s
No buffer pool page gets since the last printout
Pages read ahead 0.00/s, evicted without access 0.00/s, Random read ahead 0.00/s
LRU len: 34723, unzip_LRU len: 0
I/O sum[0]:cur[0], unzip sum[0]:cur[0]
----------------------
INDIVIDUAL BUFFER POOL INFO
----------------------
---BUFFER POOL 0
Buffer pool size 16000
Free buffers 11538
Database pages 4459
Old database pages 1625
Modified db pages 0
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 0, not young 0
0.00 youngs/s, 0.00 non-youngs/s
Pages read 387, created 4072, written 5592
0.00 reads/s, 0.00 creates/s, 0.00 writes/s
No buffer pool page gets since the last printout
Pages read ahead 0.00/s, evicted without access 0.00/s, Random read ahead 0.00/s
LRU len: 4459, unzip_LRU len: 0
I/O sum[0]:cur[0], unzip sum[0]:cur[0]
---BUFFER POOL 1
Buffer pool size 16000
Free buffers 11712
Database pages 4285
Old database pages 1563
Modified db pages 0
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 0, not young 0
0.00 youngs/s, 0.00 non-youngs/s
Pages read 373, created 3912, written 4091
0.00 reads/s, 0.00 creates/s, 0.00 writes/s
No buffer pool page gets since the last printout
Pages read ahead 0.00/s, evicted without access 0.00/s, Random read ahead 0.00/s
LRU len: 4285, unzip_LRU len: 0
I/O sum[0]:cur[0], unzip sum[0]:cur[0]
---BUFFER POOL 2
Buffer pool size 16000
Free buffers 11728
Database pages 4269
Old database pages 1557
Modified db pages 0
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 0, not young 0
0.00 youngs/s, 0.00 non-youngs/s
Pages read 283, created 3986, written 4206
0.00 reads/s, 0.00 creates/s, 0.00 writes/s
No buffer pool page gets since the last printout
Pages read ahead 0.00/s, evicted without access 0.00/s, Random read ahead 0.00/s
LRU len: 4269, unzip_LRU len: 0
I/O sum[0]:cur[0], unzip sum[0]:cur[0]
---BUFFER POOL 3
...
I/O sum[0]:cur[0], unzip sum[0]:cur[0]
---BUFFER POOL 4
....
---BUFFER POOL 5
...
---BUFFER POOL 6
....
---BUFFER POOL 7
....
--------------
ROW OPERATIONS
--------------
0 queries inside InnoDB, 0 queries in queue
0 read views open inside InnoDB
Main thread process no. 4472, id 1741499248, state: sleeping
Number of rows inserted 1222447, updated 48, deleted 1745, read 61951636
0.00 inserts/s, 0.00 updates/s, 0.00 deletes/s, 0.00 reads/s
----------------------------
END OF INNODB MONITOR OUTPUT
============================[b]2.查看Mysql事务:[/b]
2.a 查看当前事务：
mysql> select * from information_schema.INNODB_TRX;
+---------+-----------+---------------------+-----------------------+---------------------+------------+---------------------+-------------------------------+---------------------+-------------------+-------------------+------------------+-----------------------+-----------------+-------------------+-------------------------+---------------------+-------------------+------------------------+----------------------------+---------------------------+---------------------------+------------------+----------------------------+
| trx_id | trx_state | trx_started | trx_requested_lock_id | trx_wait_started | trx_weight | trx_mysql_thread_id | trx_query | trx_operation_state | trx_tables_in_use | trx_tables_locked | trx_lock_structs | trx_lock_memory_bytes | trx_rows_locked | trx_rows_modified | trx_concurrency_tickets | trx_isolation_level | trx_unique_checks | trx_foreign_key_checks | trx_last_foreign_key_error | trx_adaptive_hash_latched | trx_adaptive_hash_timeout | trx_is_read_only | trx_autocommit_non_locking |
+---------+-----------+---------------------+-----------------------+---------------------+------------+---------------------+-------------------------------+---------------------+-------------------+-------------------+------------------+-----------------------+-----------------+-------------------+-------------------------+---------------------+-------------------+------------------------+----------------------------+---------------------------+---------------------------+------------------+----------------------------+
| 1035424 | LOCK WAIT | 2017-07-18 18:17:43 | 1035424:7405:3:2 | 2017-07-18 18:17:43 | 2 | 1020087 | delete from user where id = 1 | starting index read | 1 | 1 | 2 | 312 | 1 | 0 | 0 | REPEATABLE READ | 1 | 1 | NULL | 0 | 10000 | 0 | 0 |
| 1035409 | RUNNING | 2017-07-18 18:14:35 | NULL | NULL | 4 | 1020088 | NULL | NULL | 0 | 0 | 3 | 312 | 5 | 1 | 0 | REPEATABLE READ | 1 | 1 | NULL | 0 | 10000 | 0 | 0 |
+---------+-----------+---------------------+-----------------------+---------------------+------------+---------------------+-------------------------------+---------------------+-------------------+-------------------+------------------+-----------------------+-----------------+-------------------+-------------------------+---------------------+-------------------+------------------------+----------------------------+---------------------------+---------------------------+------------------+----------------------------+
2 rows in set
mysql> 2.b 查看当前锁定的事务
mysql> SELECT * FROM INFORMATION_SCHEMA.INNODB_LOCKS;
+------------------+-------------+-----------+-----------+---------------+------------+------------+-----------+----------+-----------+
| lock_id | lock_trx_id | lock_mode | lock_type | lock_table | lock_index | lock_space | lock_page | lock_rec | lock_data |
+------------------+-------------+-----------+-----------+---------------+------------+------------+-----------+----------+-----------+
| 1035424:7405:3:2 | 1035424 | X | RECORD | `test`.`user` | PRIMARY | 7405 | 3 | 2 | 1 |
| 1035409:7405:3:2 | 1035409 | S | RECORD | `test`.`user` | PRIMARY | 7405 | 3 | 2 | 1 |
+------------------+-------------+-----------+-----------+---------------+------------+------------+-----------+----------+-----------+
2 rows in set2.c 查看当前等锁的事务
mysql> SELECT * FROM INFORMATION_SCHEMA.INNODB_LOCK_WAITS;
+-------------------+-------------------+-----------------+------------------+
| requesting_trx_id | requested_lock_id | blocking_trx_id | blocking_lock_id |
+-------------------+-------------------+-----------------+------------------+
| 1035424 | 1035424:7405:3:2 | 1035409 | 1035409:7405:3:2 |
| 1035424 | 1035424:7405:3:2 | 1035409 | 1035409:7405:3:2 |
+-------------------+-------------------+-----------------+------------------+
2 rows in set找出死锁关联的事务线程id（trx_mysql_thread_id），从上面的分析得出，持有锁的MySQL事务线程id为1020088
[b]3.Kill 关联事务线程[/b]
mysql> kill 1020088;
Query OK, 0 rows affected[b]4.再次查看当前等待锁的事务及当前事务：[/b]
mysql> SELECT * FROM INFORMATION_SCHEMA.INNODB_LOCK_WAITS;
Empty set
mysql>
SELECT * FROM INFORMATION_SCHEMA.INNODB_LOCKS;
Empty set
mysql> select * from information_schema.INNODB_TRX;
Empty set在分析之前先来看一下MySQL的锁机制，MySQLl锁机制有行级锁和表级锁,
InnoDB实现了两种类型的行锁:
共享锁（S）：允许一个事务去读一行，阻止其他事务获得相同的数据集的排他锁。
排他锁（X）：允许获得排他锁的事务更新数据，但是组织其他事务获得相同数据集的共享锁和排他锁。
共享锁就是我读的时候，你可以读，但是不能写。排他锁就是我写的时候，你不能读也不能写。其实就是MyISAM的读锁和写锁，但是针对的对象不同了而已。
除此之外InnoDB还有两个表锁：
意向共享锁（IS）：表示事务准备给数据行加入共享锁，也就是说一个数据行加共享锁前必须先取得该表的IS锁
意向排他锁（IX）：类似上面，表示事务准备给数据行加入排他锁，说明事务在一个数据行加排他锁前必须先取得该表的IX锁。
InnoDB行锁模式兼容列表，见下这篇文章
InnoDB的行锁模式及加锁方法：[url]http://lib.csdn.net/article/mysql/8747[/url]
[color=red][b]注意：[/b][/color]
当一个事务请求的锁模式与当前的锁兼容，InnoDB就将请求的锁授予该事务；反之如果请求不兼容，则该事务就等待锁释放。意向锁是InnoDB自动加的，不需要用户干预。
对于insert、update、delete，InnoDB会自动给涉及的数据加排他锁（X）；
对于一般的Select语句，InnoDB不会加任何锁，事务可以通过以下语句给显示加共享锁或排他锁。
共享锁：select * from table_name where .....lock in share mode
排他锁：select * from table_name where .....for update
[b]分析死锁原因:[/b]
出现死锁的原因，是因为会话A开启一个事务，以共享锁S锁，获取user表id为1的一行记录；
会话B，删除user表id为1记录，请求排他锁X锁，由于SX锁互斥，会话B等待会话A释放共享锁S锁，进入请求队列等待；这时，会话A删除user表id为1记录,请求排他锁X锁，但会话B在请求队列中，还轮不到会话A，会话A就等待，这种循环等待出现，死锁就出现了。
附：
这部分与上面无关，只作为记录
检查数据库表状态：
mysql> show table status from test_db;
+---------------+--------+---------+------------+------+----------------+-------------+-----------------+--------------+-----------+----------------+---------------------+-------------+------------+-----------------+----------+----------------+----------------------------------------------------------------------+
| Name | Engine | Version | Row_format | Rows | Avg_row_length | Data_length | Max_data_length | Index_length | Data_free | Auto_increment | Create_time | Update_time | Check_time | Collation | Checksum | Create_options | Comment |
+---------------+--------+---------+------------+------+----------------+-------------+-----------------+--------------+-----------+----------------+---------------------+-------------+------------+-----------------+----------+----------------+----------------------------------------------------------------------+
| user | InnoDB | 10 | Compact | 0 | 0 | 16384 | 0 | 0 | 0 | NULL | 2017-07-17 19:39:33 | NULL | NULL | utf8_general_ci | NULL | | |
| tb_message | InnoDB | 10 | Compact | 0 | 0 | 16384 | 0 | 0 | 0 | 14 | 2017-07-17 19:14:02 | NULL | NULL | utf8_general_ci | NULL | | |
| tb_log | InnoDB | 10 | Compact | 1 | 16384 | 16384 | 0 | 0 | 0 | 2 | 2017-07-18 02:00:31 | NULL | NULL | utf8_general_ci | NULL | |
+---------------+--------+---------+------------+------+----------------+-------------+-----------------+--------------+-----------+----------------+---------------------+-------------+------------+-----------------+----------+----------------+----------------------------------------------------------------------+
3 rows in setmysql>
检查指定表状态：
mysql> check table user;
+----------------------------+-------+----------+----------+
| Table | Op | Msg_type | Msg_text |
+----------------------------+-------+----------+----------+
| test_db.user | check | status | OK |
+----------------------------+-------+----------+----------+
1 row in set如果表状态不OK，则修复：
mysql> repair table user;查看数据库当前事务提交状态：
mysql> show variables like 'autocommit';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| autocommit | ON |
+---------------+-------+
1 row in set查看数据库事务隔离级别：
mysql> select @@tx_isolation;
+-----------------+
| @@tx_isolation |
+-----------------+
| REPEATABLE-READ |
+-----------------+
1 row in set
mysql>
MySQL的线程状态快照：
快照1：
mysql> show processlist
-> ;
+------+---------+-------------------+----------------+---------+------+---------------------------------+----------------------------------------------------------------------------------------------------+
| Id | User | Host | db | Command | Time | State | Info |
+------+---------+-------------------+----------------+---------+------+---------------------------------+----------------------------------------------------------------------------------------------------+
| 2721 | donald | 192.168.31.153:50725 | test_db | Query | 1070 | Waiting for table metadata lock | ALTER TABLE `user`
CHANGE COLUMN `REGISTRER_NUM` `REGISTER_NUM` varchar(13) CHARACTER SET u |
| 2724 | donald | 192.168.31.153:57376 | NULL | Sleep | 2432 | | NULL |
| 2725 | donald | 192.168.31.153:57381 | test_db | Sleep | 2423 | | NULL |
| 2727 | donald | 192.168.31.153:51135 | test_db | Sleep | 0 | | NULL |
| 2728 | donald | 192.168.31.153:51156 | test_db | Sleep | 2017 | | NULL |
| 2731 | donald | 192.168.31.153:51789 | test_db | Query | 647 | Waiting for table metadata lock | CREATE TABLE `user` (
`COM_ID` bigint(20) NOT NULL,
`BUSI_NO` varchar(32) DEFAULT NULL |
| 2735 | donald | 192.168.31.153:51813 | test_db | Query | 546 | Waiting for table metadata lock | CREATE TABLE `user` (
`COM_ID` bigint(20) NOT NULL,
`BUSI_NO` varchar(32) DEFAULT NULL |
| 2736 | donald | 192.168.31.153:58929 | test_db | Query | 0 | init | show processlist |
+------+---------+-------------------+----------------+---------+------+---------------------------------+----------------------------------------------------------------------------------------------------+
8 rows in set
快照2：
mysql> show processlist;
+---------+-----------------+-------------------+------+---------+---------+------------------------+---------------------------------------------------------------------+
| Id | User | Host | db | Command | Time | State | Info |
+---------+-----------------+-------------------+------+---------+---------+------------------------+---------------------------------------------------------------------+
| 1 | event_scheduler | localhost | NULL | Daemon | 3030806 | Waiting on empty queue | NULL |
| 1019932 | donald | 192.168.31.153:15217 | NULL | Sleep | 1526 | | NULL |
| 1019933 | donald | 192.168.31.153:15218 | test | Sleep | 1174 | | NULL |
| 1020076 | donald | 192.168.31.153:15254 | test | Query | 0 | init | show processlist |
| 1020087 | donald | 192.168.31.153:15262 | test | Sleep | 14 | | NULL |
| 1020089 | donald | 192.168.31.153:15612 | test | Query | 41 | update | INSERT INTO `user` (`id`, `name`, `age`) VALUES ('1', 'jack', '23') |
| 1020540 | donald | 192.168.31.153:16592 | test | Sleep | 64 | | NULL |
+---------+-----------------+-------------------+------+---------+---------+------------------------+---------------------------------------------------------------------+
7 rows in set