Mysql 统计数据库存储使用大小

前言在 mysql 中有一个默认的数据表 information_schema，information_schema 这张数据表保存了 MySQL 服务器所有数据库的信息。如数据库名，数据库的表，表栏的数据类型与访问权限等。

再简单点，这台 MySQL 服务器上，到底有哪些数据库、各个数据库有哪些表，每张表的字段类型是什么，各个数据库要什么权限才能访问，等等信息都保存在 information_schema 表里面，所以请勿删改此表。

代码

1，切换数据库

use information_schema; 

2，查看数据库使用大小

select concat(round(sum(data_length/1024/1024),2),’MB’) as data from tables where table_schema=’DB_Name’ ; 

3，查看表使用大小

select concat(round(sum(data_length/1024/1024),2),’MB’) as data from tables where table_schema=’DB_Name’ and table_name=’Table_Name’; 

网上找的一个，亲测可用:

先进去 MySQL 自带管理库：information_schema

然后查询 data_length,index_length

你自己的数据库名：dbname

你自己的表名：tablename

mysql> use information_schema;    
Database changed    
mysql> select data_length,index_length    
    -> from tables where    
    -> table_schema='dbname'    
    -> and table_name = 'tablename';   
+-------------+--------------+    
| data_length | index_length |    
+-------------+--------------+    
|   166379520 |    235782144 |    
+-------------+--------------+    
row in set (0.02 sec)    
mysql> select concat(round(sum(data_length/1024/1024),2),'MB') as data_length_MB,    
    -> concat(round(sum(index_length/1024/1024),2),'MB') as index_length_MB    
    -> from tables where    
    -> table_schema='dbname'    
    -> and table_name = 'tablename';   
+----------------+-----------------+    
| data_length_MB | index_length_MB |    
+----------------+-----------------+    
| 158.67MB       | 224.86MB        |    
+----------------+-----------------+    
row in set (0.03 sec) 

1. 查看所有数据库容量大小

select  
table_schema as '数据库',  
sum(table_rows) as '记录数',  
sum(truncate(data_length/1024/1024, 2)) as '数据容量(MB)',  
sum(truncate(index_length/1024/1024, 2)) as '索引容量(MB)'  
from information_schema.tables  
group by table_schema  
order by sum(data_length) desc, sum(index_length) desc;  

2.查看所有数据库各表容量大小

select  
table_schema as '数据库',  
table_name as '表名',  
table_rows as '记录数',  
truncate(data_length/1024/1024, 2) as '数据容量(MB)',  
truncate(index_length/1024/1024, 2) as '索引容量(MB)'  
from information_schema.tables  
order by data_length desc, index_length desc; 

3. 查看指定数据库容量大小

例：查看 mysql 库容量大小

select  
table_schema as '数据库',  
sum(table_rows) as '记录数',  
sum(truncate(data_length/1024/1024, 2)) as '数据容量(MB)',  
sum(truncate(index_length/1024/1024, 2)) as '索引容量(MB)'  
from information_schema.tables  
where table_schema='mysql'; 

4. 查看指定数据库各表容量大小

例：查看 mysql 库各表容量大小

select  
table_schema as '数据库',  
table_name as '表名',  
table_rows as '记录数',  
truncate(data_length/1024/1024, 2) as '数据容量(MB)',  
truncate(index_length/1024/1024, 2) as '索引容量(MB)'  
from information_schema.tables  
where table_schema='mysql'  
order by data_length desc, index_length desc;  
select concat(round(sum(data_length/1024/1024),2),'MB') as data_length_MB, concat(round(sum(index_length/1024/1024),2),'MB') as index_length_MB  
from tables  
where table_schema='passport' and table_name='tb_user_info'; 

– 569.98MB 141.98MB

select concat(round(sum(data_length/1024/1024),2),'MB') as data_length_MB, concat(round(sum(index_length/1024/1024),2),'MB') as index_length_MB  
from tables  
where table_schema='passport_v2' and table_name='tb_user_info';