Oracle查询表空间使用情况

select f.tablespace_name,a.total,u.used,f.free,round((u.used/a.total)*100 ) "% used",

  round((f.free/a.total)* 100) "% Free"

  from

  (select tablespace_name, sum(bytes/(1024 *1024)) total

       from dba_data_files group by tablespace_name) a,

  (select tablespace_name, round( sum(bytes/(1024 *1024))) used

       from dba_extents group by tablespace_name) u,

  (select tablespace_name, round( sum(bytes/(1024 *1024))) free

       from dba_free_space group by tablespace_name) f

WHERE a.tablespace_name = f.tablespace_name

and a.tablespace_name = u.tablespace_name;