結果

+--------------------+-------------+
| table_schema       | MB          |
+--------------------+-------------+
| foo                | 21.95312500 |
| footest            |  8.41354179 |
| mysql              |  0.54660702 |
| kakeibo            |  0.31250000 |
| information_schema |  0.00878906 |
| hoge               |  0.00460625 |
| performance_schema |  0.00000000 |
+--------------------+-------------+

duコマンドで確認する方法

# du /var/lib/mysql/* -s | sort -nr

43056   /var/lib/mysql/ibdata1
9440    /var/lib/mysql/footest
5132    /var/lib/mysql/ib_logfile1
5132    /var/lib/mysql/ib_logfile0
932     /var/lib/mysql/mysql
632     /var/lib/mysql/foo
212     /var/lib/mysql/performance_schema
48      /var/lib/mysql/hoge
44      /var/lib/mysql/kakeibo
4       /var/lib/mysql/mysql_upgrade_info
0       /var/lib/mysql/mysql.sock