SELECT table_schema "db명", 
            data_length / 1024 / 1024 "data", 
            index_length / 1024 / 1024 "index",
            SUM(data_length + index_length) / 1024 / 1024 "total" 
FROM information_schema.TABLES 
GROUP BY table_schema;

SELECT 
CONCAT(table_schema,'.',table_name),   
CONCAT(ROUND(table_rows/1000000,2),'Mb') 'rows',   
CONCAT(ROUND(data_length/(1024*1024),2),'Mb') 'data',   
CONCAT(ROUND(index_length/(1024*1024),2),'Mb') 'index',   
CONCAT(ROUND((data_length+index_length)/(1024*1024),2),'Mb') 'total',   
ROUND(index_length/data_length,2) idxfrac    
FROM information_schema.TABLES  
WHERE table_name = 'table명'  ;