1.查看索引
（1）单位是GB
SELECT CONCAT(ROUND(SUM(index_length)/(1024*1024*1024), 2), ' GB') AS 'Total Index Size' FROM information_schema.TABLES WHERE table_schema LIKE 'database';
+------------------+
| Total Index Size |
+------------------+
| 1.70 GB |
+------------------+
（2）单位是MB
SELECT CONCAT(ROUND(SUM(index_length)/(1024*1024), 2), ' MB') AS 'Total Index Size' FROM information_schema.TABLES WHERE table_schema LIKE 'database';
其中“database”为你所要查看的数据库
2.查看表空间
SELECT CONCAT(ROUND(SUM(data_length)/(1024*1024*1024), 2), ' GB') AS 'Total Data Size'
FROM information_schema.TABLES WHERE table_schema LIKE 'database';
+-----------------+
| Total Data Size |
+-----------------+
| 3.01 GB |
+-----------------+
3.查看数据库中所有表的信息
SELECT CONCAT(table_schema,'.',table_name) AS 'Table Name',
CONCAT(ROUND(table_rows/1000000,2),'M') AS 'Number of Rows',
CONCAT(ROUND(data_length/(1024*1024*1024),2),'G') AS 'Data Size',
CONCAT(ROUND(index_length/(1024*1024*1024),2),'G') AS 'Index Size' ,
CONCAT(ROUND((data_length+index_length)/(1024*1024*1024),2),'G') AS'Total'FROM information_schema.TABLES WHERE table_schema LIKE 'database';
