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前言:在mysql中有一個默認的數據表information_schema
,information_schema這張數據表保存了MySQL服務器所有數據庫的信息。如數據庫名,數據庫的表,表欄的數據類型與訪問權限等。再簡單點,這台MySQL服務器上,到底有哪些數據庫、各個數據庫有哪些表,每張表的字段類型是什么,各個數據庫要什么權限才能訪問,等等信息都保存在information_schema表里面,所以請勿刪改此表。
代碼:
1,切換數據庫
use information_schema
;
2,查看數據庫使用大小
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’;
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網上找的一個,親測可用:
//先進去MySQL自帶管理庫:information_schema
//然后查詢 data_length,index_length
//你自己的數據庫名: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)
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1.查看所有數據庫容量大小
select table_schema as '數據庫', sum(table_rows) as '記錄數', sum(truncate(data_length/1024/1024, 2)) as '數據容量(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.查看所有數據庫各表容量大小
select table_schema as '數據庫', table_name as '表名', table_rows as '記錄數', truncate(data_length/1024/1024, 2) as '數據容量(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.查看指定數據庫容量大小
例:查看mysql庫容量大小
select table_schema as '數據庫', sum(table_rows) as '記錄數', sum(truncate(data_length/1024/1024, 2)) as '數據容量(MB)', sum(truncate(index_length/1024/1024, 2)) as '索引容量(MB)' from information_schema.tables where table_schema='mysql';
4.查看指定數據庫各表容量大小
例:查看mysql庫各表容量大小
select table_schema as '數據庫', table_name as '表名', table_rows as '記錄數', truncate(data_length/1024/1024, 2) as '數據容量(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