统计mysql数据库每个库的大小，表总数等。

作用:统计每个库的真实数据与索引数据的总和的大小单位为MB，真实数据的大小单位MB，索引数据的大小MB，含有表的总数，当前日期。并且以每个库的大小倒序排序。

 

SELECT   table_schema,\

         SUM(data_length+index_length)/1024/1024 AS total_mb,\

         SUM(data_length)/1024/1024 AS data_mb,\

         SUM(index_length)/1024/1024 AS index_mb,\

         COUNT(*) AS tables,\

         CURDATE() AS today \

FROM     information_schema.tables \

GROUP BY table_schema \

ORDER BY 2 DESC;