mysql日常运维

1. mysql查看数据库大小

use 数据库名

SELECT sum(DATA_LENGTH)+sum(INDEX_LENGTH) FROM information_schema.TABLES where TABLE_SCHEMA='数据库名';

2. mysql表占用的空间

SELECT TABLE_NAME,DATA_LENGTH+INDEX_LENGTH,TABLE_ROWS FROM TABLES WHERE TABLE_SCHEMA='数据库名' AND TABLE_NAME='表名'

3. 查看表的最后mysql修改时间

select TABLE_NAME,UPDATE_TIME from INFORMATION_SCHEMA.tables where TABLE_SCHEMA='数据库名';

4.查看当前的连接数

 show status like 'Threads%';

+-------------------+--------+

| Variable_name     | Value  |

+-------------------+--------+

| Threads_cached    | 2      |

| Threads_connected | 1183   |   //当前连接数

| Threads_created   | 337798 |

| Threads_running   | 13     |   //当前的并发数

+-------------------+--------+

5.查看最大连接数

show variables like '%max_connections%';

+-----------------+-------+

| Variable_name   | Value |

+-----------------+-------+

| max_connections | 8200  |

+-----------------+-------+

1 row in set (0.01 sec)

6.查看QPS

QPS (Query per second) （每秒查询量）

 SHOW GLOBAL STATUS LIKE 'Questions';

+---------------+-------------+

| Variable_name | Value       |

+---------------+-------------+

| Questions     | 42260778868 |

+---------------+-------------+

1 row in set (0.00 sec)

 SHOW GLOBAL STATUS LIKE 'Uptime';

+---------------+----------+

| Variable_name | Value    |

+---------------+----------+

| Uptime        | 26924936 |

+---------------+----------+

1 row in set (0.00 sec)

select 42260778868/26924936 AS QPS  from dual;

+-----------+

| QPS       |

+-----------+

| 1569.5777 |

+-----------+

1 row in set (0.00 sec)

7.查看tps

TPS(Transaction per second) （每秒事务量，如果是InnoDB会显示，没有InnoDB就不会显示）

 SHOW GLOBAL STATUS LIKE 'Com_commit';

+---------------+---------+

| Variable_name | Value   |

+---------------+---------+

| Com_commit    | 1676595 |

+---------------+---------+

1 row in set (0.00 sec)

SHOW GLOBAL STATUS LIKE 'Com_rollback';

+---------------+-------+

| Variable_name | Value |

+---------------+-------+

| Com_rollback  | 1     |

+---------------+-------+

1 row in set (0.01 sec)

  SHOW GLOBAL STATUS LIKE 'Uptime';

+---------------+----------+

| Variable_name | Value    |

+---------------+----------+

| Uptime        | 26925163 |

+---------------+----------+

1 row in set (0.00 sec)

select (1676595+1)/26925163 as TPS from dual;

+--------+

| TPS    |

+--------+

| 0.0623 |

+--------+
1 row in set (0.00 sec)

8. 登陆

mysql -h $IP -P $PORT -u $USER -p'$pw' -D 数据库名