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2023-05-24
MySQL查看表占用空间大小
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 ```sql 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';
-- 2128.94MB 285.00MB
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