If you want to see how much actual data is stored in your MyISAM, InnoDB:

SELECT IFNULL(B.engine,'Total') "Storage Engine",
 CONCAT(LPAD(REPLACE(FORMAT(B.DSize/POWER(1024,pw),3),',',''),17,' '),' ',
 SUBSTR(' KMGTP',pw+1,1),'B') "Data Size", CONCAT(LPAD(REPLACE(
 FORMAT(B.ISize/POWER(1024,pw),3),',',''),17,' '),' ',
 SUBSTR(' KMGTP',pw+1,1),'B') "Index Size", CONCAT(LPAD(REPLACE(
 FORMAT(B.TSize/POWER(1024,pw),3),',',''),17,' '),' ',
 SUBSTR(' KMGTP',pw+1,1),'B') "Table Size"
 FROM (SELECT engine,SUM(data_length) DSize,SUM(index_length) ISize,
 SUM(data_length+index_length) TSize FROM information_schema.tables
 WHERE table_schema NOT IN ('mysql','information_schema','performance_schema')
 AND engine IS NOT NULL GROUP BY engine WITH ROLLUP) B,
 (SELECT 3 pw) A ORDER BY TSize;

#mysql #myisam #innodb #storage_engine #se