oracle查询当前实例占用存储最大的500张表

查询字段：用户名、表名、表空间、占用存储、创建时间、最后一次更新时间

select a.*, rownum, b.CREATED, b.LAST_DDL_TIME
  from (select a.owner,
               a.segment_name,
               a.tablespace_name,
               sum(a.bytes) / 1024 / 1024 Mbytes
          from dba_segments a
         where a.segment_type = 'TABLE'
         group by a.owner, a.segment_name, a.tablespace_name
         order by sum(bytes) desc) a
 inner join dba_objects b
    on a.owner = b.owner
   and a.segment_name = b.OBJECT_NAME
   and b.OBJECT_TYPE = 'TABLE'
 where rownum <= 500 ;