慢查询日志记录状态
show variables like 'slow%';
查询慢查询日记记录超时时间
show variables like 'long_query_time';
设置慢查询超时时间
set global long_query_time=1;
设置慢查询
set global slow_query_log=ON;
1、查询是否锁表
show OPEN TABLES where In_use > 0;
2、查询进程
show processlist
查询到相对应的进程===然后 kill id
补充:
查看正在锁的事务
SELECT * FROM INFORMATION_SCHEMA.INNODB_LOCKS;
查看等待锁的事务
SELECT * FROM INFORMATION_SCHEMA.INNODB_LOCK_WAITS;
select * from innodb_locks \G;
select * from innodb_trx\G;
select * from innodb_lock_waits\G;
show processlist\G;
SHOW ENGINE INNODB STATUS\G;
mysql 备份恢复(mysqldump linux)
mysqldump -uroot -p [database name] > [dump file]
mysql -uroot -p [database name] < [dump file]
mysql事物相关
查询当前事物级别
select @@tx_isolation;
设置事物级别:
set session transaction isolation level read uncommitted;
mysql用户:
select Host,User,Password from mysql.user;
创建用户:create user test identified by '123456';
授权:grant all privileges on *.* to 'test'@'%'identified by '123456' with grant option;
all代表接受所有操作,比如 select,insert,delete....; *.* 代表所有库下面的所有表;% 代表这个用户允许从任何地方登录;为了安全期间,这个%可以替换为你允许的ip地址
最后刷新:flush privileges;
修改密码:update mysql.user set password=password('新密码') where User="test" and Host="localhost";
删除用户:delete from user where User='test' and Host='localhost';