Show the ten largest objects in the database

col owner format a15
col segment_name format a30
col segment_type format a15
col mb format 999,999,999
select  owner
, segment_name
, segment_type
, mb
from (
 select owner
 , segment_name
 , segment_type
 , bytes / 1024 / 1024 "MB"
 from dba_segments
 order by bytes desc
 )
where rownum < 11
/