查看mysql库大小，表大小，索引大小

说明：通过MySQL的 information_schema 数据库，可查询数据库中每个表占用的空间、表记录的行数；该库中有一个 TABLES 表，这个表主要字段分别是：TABLE_SCHEMA : 数据库名TABLE_NAME：表名ENGINE：所使用的存储引擎TABLES_ROWS：记录数DATA_LENGTH：数据大小INDEX_LENGTH：索引大小其他字段请参考MySQL的手册，查看一个表占用空间的大小，那就相当于是 数据大小 + 索引大小 。

查看所有库的大小

mysql> use information_schema;Database changedmysql> select concat(round(sum(DATA_LENGTH/1024/1024),2),'MB') as data  from TABLES;+----------+| data     |+----------+| 104.21MB |+----------+1 row in set (0.11 sec)

查看指定库的大小

mysql> select concat(round(sum(DATA_LENGTH/1024/1024),2),'MB') as data  from TABLES where table_schema='jishi';+---------+| data    |+---------+| 26.17MB |+---------+1 row in set (0.01 sec)

查看指定库的指定表的大小

mysql> select concat(round(sum(DATA_LENGTH/1024/1024),2),'MB') as data  from TABLES where table_schema='jishi' and table_name='a_ya';+--------+| data   |+--------+| 0.02MB |+--------+1 row in set (0.00 sec)

查看指定库的索引大小

mysql> SELECT CONCAT(ROUND(SUM(index_length)/(1024*1024), 2), ' MB') AS 'Total Index Size' FROM TABLES  WHERE table_schema = 'jishi';+------------------+| Total Index Size |+------------------+| 0.94 MB          |+------------------+1 row in set (0.01 sec)

查看指定库的指定表的索引大小

mysql> SELECT CONCAT(ROUND(SUM(index_length)/(1024*1024), 2), ' MB') AS 'Total Index Size' FROM TABLES  WHERE table_schema = 'test' and table_name='a_yuser';+------------------+| Total Index Size |+------------------+| 21.84 MB         |+------------------+1 row in set (0.00 sec)mysql> show create table test.a_yuser\G;*************************** 1. row ***************************       Table: a_yuserCreate Table: CREATE TABLE `a_yuser` (  `email` varchar(60) NOT NULL DEFAULT '',  `user_name` varchar(60) NOT NULL DEFAULT '',  KEY `cc` (`email`(5)),  KEY `ccb` (`user_name`(5)),  KEY `ccbc` (`email`(5),`user_name`(5))) ENGINE=MyISAM DEFAULT CHARSET=utf81 row in set (0.00 sec)  ERROR:No query specified  mysql> select count(*) from test.a_yuser;+----------+| count(*) |+----------+|  1073607 |+----------+1 row in set (0.00 sec)

查看一个库中的情况

mysql>  SELECT CONCAT(table_schema,'.',table_name) AS 'Table Name', CONCAT(ROUND(table_rows/1000000,4),'M') AS 'Number of Rows', CONCAT(ROUND(data_length/(1024*1024*1024),4),'G') AS 'Data Size', CONCAT(ROUND(index_length/(1024*1024*1024),4),'G') AS 'Index Size', CONCAT(ROUND((data_length+index_length)/(1024*1024*1024),4),'G') AS'Total'FROM information_schema.TABLES WHERE table_schema LIKE 'test';+---------------+----------------+-----------+------------+---------+| Table Name    | Number of Rows | Data Size | Index Size | Total   |+---------------+----------------+-----------+------------+---------+| test.a_br     | 0.4625M        | 0.0259G   | 0.0171G    | 0.0431G || test.a_skuclr | 0.7099M        | 0.0660G   | 0.0259G    | 0.0919G || test.a_yuser  | 1.0736M        | 0.0497G   | 0.0213G    | 0.0710G || test.test     | 0.0000M        | 0.0000G   | 0.0000G    | 0.0000G |+---------------+----------------+-----------+------------+---------+4 rows in set (0.13 sec)

当时做记录的时候忘记记录原文链接了,作者看到之后可以私信我,我补上原文链接.