查看mysql中某个数据库或表占用的磁盘空间（最新修正）

    近日在运行下面的命令发现无效，经查询发现是mysql早期版本不支持数据字典功能，仅在5.0及更高版本才能使用数据字典查询所占磁盘空间，下面给出各种数据库支持数据字典的版本。

 

Microsoft SQL Server - Supported in Version 7 and up
MySQL - Supported in Version 5 and up
PostgreSQL - Supported in Version 7.4 and up
Oracle - Does not appear to be supported
Apache Derby - NOT Supported As of Version 10.3

 

附转载网址：

 

查整个库的状态：
select concat(truncate(sum(data_length)/1024/1024,2),'MB') as data_size,
concat(truncate(sum(max_data_length)/1024/1024,2),'MB') as max_data_size,
concat(truncate(sum(data_free)/1024/1024,2),'MB') as data_free,
concat(truncate(sum(index_length)/1024/1024,2),'MB') as index_size
from information_schema.tables where TABLE_SCHEMA = 'databasename';

查单表：
select concat(truncate(sum(data_length)/1024/1024,2),'MB') as data_size,
concat(truncate(sum(max_data_length)/1024/1024,2),'MB') as max_data_size,
concat(truncate(sum(data_free)/1024/1024,2),'MB') as data_free,
concat(truncate(sum(index_length)/1024/1024,2),'MB') as index_size
from information_schema.tables where TABLE_NAME = 'tablename';