简单介绍
在 Oracle 10g 以前的版本，更改表空间名字是几乎不可能的事情，除非删除，重新创建，大费周章。Oracle 10g 新添加了一项更改表空间名字的功能，使得更改表空间名字瞬间即可完成。是个较为人性化的功能。
SQL> COL FILE_NAME format a70
SQL> SET linesize 120
SQL> SET pagesize 99
SQL> COL TABLESPACE_NAME format a10
SQL>
SQL> SELECT file_name, tablespace_name FROM dba_data_files;
FILE_NAME TABLESPACE
---------------------------------------------------------------------- ----------
/u01/app/oracle/prodUCt/10.1.0/db_1/oradata/TEST/users01.dbf USERS
/u01/app/oracle/product/10.1.0/db_1/oradata/TEST/sysaux01.dbf SYSAUX
/u01/app/oracle/product/10.1.0/db_1/oradata/TEST/undotbs01.dbf UNDOTBS1
/u01/app/oracle/product/10.1.0/db_1/oradata/TEST/system01.dbf SYSTEM
/u01/app/oracle/product/10.1.0/db_1/oradata/TEST/example01.dbf EXAMPLE
/u01/app/oracle/product/10.1.0/db_1/oradata/TEST/foo1.dbf FOO
6 rows selected.
该命令的语法很简单:
ALTER TABLESPACE tablespacename RENAME TO newtablespacename;
tablespacename 和newtablespacename 分别对应原来的表空间名字和更改后的表空间名字：
实战演练
注重：在操作前后都请做好控制文件的备份工作
SQL>ALTER TABLESPACE foo RENAME TO test;
Tablespace altered.
SQL> SELECT file_name, tablespace_name FROM dba_data_files;
FILE_NAME TABLESPACE
---------------------------------------------------------------------- ----------
/u01/app/oracle/product/10.1.0/db_1/oradata/TEST/users01.dbf USERS
/u01/app/oracle/product/10.1.0/db_1/oradata/TEST/sysaux01.dbf SYSAUX
/u01/app/oracle/product/10.1.0/db_1/oradata/TEST/undotbs01.dbf UNDOTBS1
/u01/app/oracle/product/10.1.0/db_1/oradata/TEST/system01.dbf SYSTEM
/u01/app/oracle/product/10.1.0/db_1/oradata/TEST/example01.dbf EXAMPLE
/u01/app/oracle/product/10.1.0/db_1/oradata/TEST/foo1.dbf TEST
因为 system 和 sysaux 这两个表空间的非凡性，是不可以更名的:
SQL> ALTER TABLESPACE system RENAME TO mysystem;
ALTER TABLESPACE system RENAME TO mysystem
*
ERROR at line 1:
ORA-00712: cannot rename system tablespace
SQL> ALTER TABLESPACE sysaux RENAME TO mysysaux;
ALTER TABLESPACE sysaux RENAME TO mysysaux
*
ERROR at line 1:
ORA-13502: Cannot rename SYSAUX tablespace
可以对 undo tablespace 重新命名，假如使用的是 spfile ,而不是 pfile, Oracle 会自动对 spfile 中的 undo_tablespace 进行更改(不过要在数据库重新启动之后才可以观察到), 假如使用的是 pfile ,要对其进行手工更改。我们看看 spfile 的变化情况：
SQL> ALTER tablespace undotbs1 RENAME TO undotbs;
Tablespace altered.
SQL>
SQL> show parameter pfile
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
spfile string /u01/app/oracle/product/10.1.0
/db_1/dbs/spfileTEST.ora
SQL> show parameters undo
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
undo_management string AUTO
undo_retention integer 900
undo_tablespace string UNDOTBS1
SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup
ORACLE instance started.
Total System Global Area 180355072 bytes
Fixed Size 777996 bytes
Variable Size 128983284 bytes
Database Buffers 50331648 bytes
Redo Buffers 262144 bytes
Database mounted.
Database opened.
SQL> show parameters undo
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
undo_management string AUTO
undo_retention integer 900
undo_tablespace string UNDOTBS
SQL>
对脱机表空间的更名是不答应的：
SQL> ALTER TABLESPACE TEST OFFLINE;
Tablespace altered.
SQL> ALTER TABLESPACE test RENAME TO testoffline;
ALTER TABLESPACE test RENAME TO testoffline
*
ERROR at line 1:
ORA-01135: file 6 Accessed for DML/query is offline
ORA-01110: data file 6:
'/u01/app/oracle/product/10.1.0/db_1/oradata/TEST/foo1.dbf'
给出的提示信息很有参考价值：更名操作是要对表空间进行 DML/query 操作的，表空间offline的话，则不可以。
那么假如表空间是只读的会怎么样呢？
SQL> ALTER TABLESPACE TEST ONLINE;
Tablespace altered.
SQL> ALTER TABLESPACE TEST READ ONLY;
Tablespace altered.
SQL> ALTER TABLESPACE test RENAME TO testreadonly;
Tablespace altered.
SQL> list
1* SELECT file_name, tablespace_name FROM dba_data_files
SQL> /
FILE_NAME TABLESPACE
---------------------------------------------------------------------- ----------
/u01/app/oracle/product/10.1.0/db_1/oradata/TEST/users01.dbf USERS
/u01/app/oracle/product/10.1.0/db_1/oradata/TEST/sysaux01.dbf SYSAUX
/u01/app/oracle/product/10.1.0/db_1/oradata/TEST/undotbs01.dbf UNDOTBS
/u01/app/oracle/product/10.1.0/db_1/oradata/TEST/system01.dbf SYSTEM
/u01/app/oracle/product/10.1.0/db_1/oradata/TEST/example01.dbf EXAMPLE
/u01/app/oracle/product/10.1.0/db_1/oradata/TEST/foo1.dbf TESTREADONLY
6 rows selected.
SQL>
看来数据字典已经更新，不过Oracle会向alert_SID.log 中写入类似如下的日志:
ALTER TABLESPACE test RENAME TO testreadonly
Sat Nov 13 16:15:21 2004
Tablespace 'TEST' is renamed to 'TESTREADONLY'.
Tablespace name change is not propagated to file headersbecause the tablespace is read only.
Completed: ALTER TABLESPACE test RENAME TO testreadonly
注重Log里有个细微的小Bug：headersbecause。这是两个词，应该空开的 :-)
限制条件
应用这个特性有个主要的限制条件：COMPATIBLE 初始化参数要求为 10.0 或者更高才可以
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