Oracle表空间使用情况查看
--查看数据文件
SQL> select file_name from dba_data_files;
FILE_NAME
--------------------------------------------------
/oradata/lianxi/users01.dbf
/oradata/lianxi/sysaux01.dbf
/oradata/lianxi/undotbs01.dbf
/oradata/lianxi/system01.dbf
--查看临时数据文件，发现没有，是因为之前做过重建控制文件导致的，需要重新加载临时文件
SQL> select file_name from dba_temp_files;
no rows selected
--给临时表空间加临时数据文件
SQL> alter tablespace temp add tempfile '/oradata/lianxi/temp01.dbf';
Tablespace altered.
--查看临时数据文件
SQL> select file_name from dba_temp_files;
FILE_NAME
--------------------------------------------------
/oradata/lianxi/temp01.dbf
--查看数据文件大小
SQL> select tablespace_name,sum(bytes)/1024/1024 "size(M)" from dba_data_files group by tablespace_name;
TABLESPACE_NAME size(M)
------------------------------ ----------
SYSAUX 250
UNDOTBS1 210
USERS 50
SYSTEM 480
--查看临时数据文件大小
SQL> select tablespace_name,sum(bytes)/1024/1024 "size(M)" from dba_temp_files group by tablespace_name ;
TABLESPACE_NAME size(M)
------------------------------ ----------
TEMP 25
--查看表空间已经使用空间大小
SQL> select tablespace_name,sum(bytes)/1024/1024 "used(M)" from dba_segments group by tablespace_name order by tablespace_name;
TABLESPACE_NAME used(M)
------------------------------ ----------
SYSAUX 238.125
SYSTEM 476.8125
UNDOTBS1 20.1875
USERS .625
--查看表空间剩余空间大小，发现系统表空间所剩不多了
SQL> select tablespace_name,sum(bytes)/1024/1024 "free(M)" from dba_free_space group by tablespace_name order by tablespace_name;
TABLESPACE_NAME free(M)
------------------------------ ----------
SYSAUX 12.125
SYSTEM 3.125
UNDOTBS1 189.75
USERS 49.3125
--查看临时表空间使用情况
SQL> select tablespace_name,sum(bytes_used)/1024/1024 "used(M)",sum(bytes_free)/1024/1024 "free(M)" from v$temp_space_header group by tablespace_name;
TABLESPACE_NAME used(M) free(M)
------------------------------ ---------- ----------
TEMP 1 24
--增加系统表空间大小
SQL> alter database datafile '/oradata/lianxi/system01.dbf' resize 500M;
Database altered.
SQL> select tablespace_name,sum(bytes)/1024/1024 "size(M)" from dba_data_files group by tablespace_name;
TABLESPACE_NAME size(M)
------------------------------ ----------
SYSAUX 250
UNDOTBS1 210
USERS 50
SYSTEM 500
删除用户和表空间：
drop user k3admin
再删除表空间
drop tablespace K3CLOUD_DATA including contents and datafiles;
drop tablespace K3CLOUD_DATA_TEMP including contents and datafiles;
drop user clouduser cascade
drop tablespace K3CLOUD6_DATA including contents and datafiles;
drop tablespace CLOUD6_DATA_TEMP including contents and datafiles;
查看连接及清除连接
select username,sid,serial# from v$session
alter system kill session '75,3259'
alter system kill session '9,79'
转自：
http://blog.sina.com.cn/s/blog_697e5aec010114tn.html