oracle 数据库中的空间大小管理

某个用户中所有表的大小排序

SELECT   segment_name, SUM (BYTES / 1024 / 1024) table_size_m
    FROM user_segments
GROUP BY segment_name
ORDER BY table_size_M desc 

数据库中所有用户的空间大小排序

SELECT owner, tablespace_name, SUM (BYTES/1024/1024) AS size_m
  FROM dba_segments group by owner,tablespace_name
  order by size_m desc