select 'sfc' db, (sum(DATA_LENGTH)+sum(INDEX_LENGTH))/1024/1024/1024 'SIZE' from information_schema.tables
where table_schema='sfc'
union
select 'smt' db, (sum(DATA_LENGTH)+sum(INDEX_LENGTH))/1024/1024/1024 'SIZE' from information_schema.tables
where table_schema='smt';