oracle查询表空间的空间占用情况

select a.tablespace_name,a.bytes bytes_used,b.largest,round(((a.bytes - b.bytes)/a.bytes)*100,2) percent_used
from (select tablespace_name,sum(bytes) bytes from dba_data_files group by tablespace_name) a,
(select tablespace_name,sum(bytes) bytes,max(bytes) largest from dba_free_space group by tablespace_name) b
where a.tablespace_name=b.tablespace_name order by ((a.bytes - b.bytes) / a.bytes) desc

select a.tablespace_name,a.bytes/1024/1024 "Sum MB",(a.bytes-b.bytes)/1024/1024 "used MB",b.bytes/1024/1024 "free MB",
round(((a.bytes-b.bytes)/a.bytes)*100,2) "percent_used"
from
(select tablespace_name,sum(bytes) bytes from dba_data_files group by tablespace_name) a,
(select tablespace_name,sum(bytes) bytes,max(bytes) largest from dba_free_space group by tablespace_name) b
where a.tablespace_name=b.tablespace_name
order by ((a.bytes-b.bytes)/a.bytes) desc

查询所有表空间的总容量、已经使用、剩余、已经使用的百分比！

select a.tablespace_name,a.bytes/1024/1024 "Sum MB",(a.bytes-b.bytes)/1024/1024 "used MB",b.bytes/1024/1024 "free MB",
round(((a.bytes-b.bytes)/a.bytes)*100,2) "percent_used"
from
(select tablespace_name,sum(bytes) bytes from dba_data_files group by tablespace_name) a,
(select tablespace_name,sum(bytes) bytes,max(bytes) largest from dba_free_space group by tablespace_name) b
where a.tablespace_name=b.tablespace_name
order by ((a.bytes-b.bytes)/a.bytes) desc

一般来说可以把上面的复杂的查询语句放入一个文件中，需要时再调用，或者创建一个试图，需要时可以查询。
1 写入文件:#vi /home/mzl/percent_used_tablespace.sql
内容：
select a.tablespace_name,a.bytes/1024/1024 "Sum MB",(a.bytes-b.bytes)/1024/1024 "used MB",b.bytes/1024/1024 "free MB",
round(((a.bytes-b.bytes)/a.bytes)*100,2) "percent_used"
from
(select tablespace_name,sum(bytes) bytes from dba_data_files group by tablespace_name) a,
(select tablespace_name,sum(bytes) bytes,max(bytes) largest from dba_free_space group by tablespace_name) b
where a.tablespace_name=b.tablespace_name
order by ((a.bytes-b.bytes)/a.bytes) desc

2 导入：
SQL> @/home/mzl/percent_used_tablespace.sql
SQL> l
1 select a.tablespace_name,a.bytes "Sum",a.bytes-b.bytes "used",b.bytes "free",
2 round(((a.bytes-b.bytes)/a.bytes)*100,2) "percent_used"
3 from
4 (select tablespace_name,sum(bytes) bytes from dba_data_files group by tablespace_name) a,
5 (select tablespace_name,sum(bytes) bytes,max(bytes) largest from dba_free_space group by tablespace_name) b
6 where a.tablespace_name=b.tablespace_name
7* order by ((a.bytes-b.bytes)/a.bytes) desc
SQL> /

或者创建视图：
SQL>create view percent
SQL>as
SQL>select a.tablespace_name,a.bytes/1024/1024 "Sum MB",(a.bytes-b.bytes)/1024/1024 "used MB",b.bytes/1024/1024 "free MB",
SQL>round(((a.bytes-b.bytes)/a.bytes)*100,2) "percent_used"
SQL>from
SQL>(select tablespace_name,sum(bytes) bytes from dba_data_files group by tablespace_name) a,
SQL>(select tablespace_name,sum(bytes) bytes,max(bytes) largest from dba_free_space group by tablespace_name) b
SQL>where a.tablespace_name=b.tablespace_name
SQL>order by ((a.bytes-b.bytes)/a.bytes) desc;

SQL> select * from percent;

查看表空间的数据文件是否是自动扩展：
SQL> l
1* select file_name,tablespace_name,autoextensible from dba_data_files
SQL> /

FILE_NAME TABLESPACE_NAME AUT
--------------------------------------------- ------------------------------ ---
/u01/app/oracle/oradata/orcl/risenet.dbf RISENET
/u01/app/oracle/oradata/orcl/perfstat.dbf PERFSTAT NO
/u01/app/oracle/oradata/orcl/example01.dbf EXAMPLE YES
/u01/disk1/users01.dbf USERS YES
/u01/app/oracle/oradata/orcl/sysaux01.dbf SYSAUX YES
/u01/app/oracle/oradata/orcl/undotbs01.dbf UNDOTBS1
/u01/disk2/system01.dbf SYSTEM YES
/u01/app/oracle/oradata/orcl/undotbs02.dbf UNDOTBS2 NO
/u01/disk1/pioneer_data.dbf PIONEER_DATA YES
/u01/disk2/pioneer_indx.dbf PIONEER_INDX NO
/u01/disk3/pioneer_undo.dbf PIONEER_UNDO NO

FILE_NAME TABLESPACE_NAME AUT
--------------------------------------------- ------------------------------ ---
/u01/app/oracle/oradata/orcl/paul01.dbf PAUL NO
/u01/disk1/wenchuan.dbf WENCHUAN NO

13 rows selected.

比如表空间PIONEER_INDX已经用了83.33％，数据文件不能自动扩展，可以修改成自动扩展，以免数据写满数据文件。
SQL> alter database
2 datafile '/u01/disk2/pioneer_indx.dbf' autoextend on;

Database altered.

SQL> select file_name,tablespace_name,autoextensible from dba_data_files
2 where tablespace_name='PIONEER_INDX';

FILE_NAME TABLESPACE_NAME AUT
--------------------------------------------- ------------------------------ ---
/u01/disk2/pioneer_indx.dbf PIONEER_INDX YES

或者给表空间多加一个自动扩展的数据文件,如果有多个硬盘，可以增加多个数据文件（这样多数据库系统的并发性比较好）
SQL> alter tablespace pioneer_indx
2 add datafile size 30M;

Tablespace altered.

SQL> select file_name,tablespace_name,bytes/1024/1024 "MB" from dba_data_files
2 where tablespace_name='PIONEER_INDX';

FILE_NAME TABLESPACE_NAME
--------------------------------------------- ------------------------------
MB
----------
/u01/disk2/pioneer_indx.dbf PIONEER_INDX
6

/u01/disk5/ORCL/datafile/o1_mf_pioneer__45dpy PIONEER_INDX
fty_.dbf
30