【查询Oracle表空间信息】

1.查看当前用户每个表占用空间的大小：
     Select Segment_Name,Sum(bytes)/1024/1024 From User_Extents Group By Segment_Name;

2.查看每个表空间占用空间的大小：
      Select Tablespace_Name,Sum(bytes)/1024/1024 From Dba_Segments Group By Tablespace_Name;

3.查询出当前用户的表所占用的空间大小，并按大小进行降序排列：
      Select Segment_Name,Sum(bytes)/1024/1024 From User_Extents Group By Segment_Name order by Sum(bytes)/1024/1024 desc;

4.查询出系统表空间的大小，并按大小进行降序排列(需要SYSDBA的权限)：
      Select Tablespace_Name,Sum(bytes)/1024/1024 From Dba_Segments Group By Tablespace_Name order by Sum(bytes)/1024/1024 desc;

5.服务器空间

[root@localhost ~]# df -h

Filesystem            容量    已用 可用 已用% 挂载点

/dev/mapper/VolGroup00-LogVol00

                       21G   16G 3.9G 80% /

/dev/mapper/VolGroup00-LogVol01

                       40G   38G 4.0M 100% /app

/dev/cciss/c0d0p1      99M   15M   80M 16% /boot

none                  3.9G     0 3.9G   0% /dev/shm

/app目录是oracle目录，总共40G，已经用了38G 使用了100％

6.oracle查询表空间使用情况语句

SELECT UPPER(F.TABLESPACE_NAME) "表空间名",
       D.TOT_GROOTTE_MB "表空间大小(M)",
       D.TOT_GROOTTE_MB - F.TOTAL_BYTES "已使用空间(M)",
       TO_CHAR(ROUND((D.TOT_GROOTTE_MB - F.TOTAL_BYTES) / D.TOT_GROOTTE_MB * 100,
                     2),
               '990.99') "使用比",
       F.TOTAL_BYTES "空闲空间(M)",
       F.MAX_BYTES "最大块(M)"
FROM (SELECT TABLESPACE_NAME,
               ROUND(SUM(BYTES) / (1024 * 1024), 2) TOTAL_BYTES,
               ROUND(MAX(BYTES) / (1024 * 1024), 2) MAX_BYTES
          FROM SYS.DBA_FREE_SPACE
         GROUP BY TABLESPACE_NAME) F,
       (SELECT DD.TABLESPACE_NAME,
               ROUND(SUM(DD.BYTES) / (1024 * 1024), 2) TOT_GROOTTE_MB
          FROM SYS.DBA_DATA_FILES DD
         GROUP BY DD.TABLESPACE_NAME) D
WHERE D.TABLESPACE_NAME = F.TABLESPACE_NAME
ORDER BY 4 DESC; 

或者

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;