select * from
 (select 
   s.SEGMENT_NAME, 
   s.SEGMENT_TYPE, 
   (s.BYTES/1024/1024/1024) GB, 
   t.LAST_ANALYZED 
from 
   dba_segments s,
   dba_tables t
WHERE
t.table_name = s.SEGMENT_NAME
and t.LAST_ANALYZED <trunc(SYSDATE) - 7
order by 3 desc)
WHERE
ROWNUM <=10
;