FIND SCHEMA(USER) SIZE

SCHEMA(USER) SIZE

select obj.owner "Owner"
, obj_cnt "Objects"
, decode(seg_size, NULL, 0, seg_size) "size MB"
from (select owner, count(*) obj_cnt from dba_objects group by owner) obj
, (select owner, ceil(sum(bytes)/1024/1024) seg_size
 from dba_segments group by owner) seg
where obj.owner = seg.owner(+)
order by 3 desc ,2 desc, 1;