SELECT DBName,CONCAT(LPAD(FORMAT(SDSize/POWER(1024,pw),3),17,' '),' ',
SUBSTR(' KMGTP',pw+1,1),'B') "DataSize",
CONCAT(LPAD(FORMAT(SXSize/POWER(1024,pw),3),17,' '),' ',
SUBSTR(' KMGTP',pw+1,1),'B') "IndexSize",
CONCAT(LPAD(FORMAT(STSize/POWER(1024,pw),3),17,' '),' ',
SUBSTR(' KMGTP',pw+1,1),'B') "Total Size"
FROM (SELECT IFNULL(DB,'All Databases') DBName,SUM(DSize) SDSize,
SUM(XSize) SXSize,SUM(TSize) STSize
FROM (SELECT table_schema DB,data_length DSize,index_length XSize,
data_length+index_length TSize FROM information_schema.tables WHERE
table_schema NOT IN ('mysql','information_schema','performance_schema')) AAA
GROUP BY DB WITH ROLLUP) AA,(SELECT 2 pw) BB ORDER BY (SDSize+SXSize) DESC
dba.stackexchange.com/a/18952