oracle表空间更名

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> 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
1.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：

2.实战演练
注意：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

3.因为 system 和 sysaux 这两个表空间的特殊性，是不可以更名的:
SQL> ALTER TABLESPACE system RENAME TO mysystem;
ORA-00712: cannot rename system tablespace
SQL> ALTER TABLESPACE sysaux RENAME TO mysysaux;
ORA-13502: Cannot rename SYSAUX tablespace

4.可以对 undo tablespace 重新命名，如果使用的是 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), 如果使用的是 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;
SQL> startup
SQL> show parameters undo
NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
undo_management                      string      AUTO
undo_retention                       integer     900
undo_tablespace                      string      UNDOTBS

5.对脱机表空间的更名是不允许的：
SQL> ALTER TABLESPACE TEST OFFLINE;
Tablespace altered.
SQL> ALTER TABLESPACE test RENAME TO testoffline;             
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。
6.那么如果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

7.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
注意Log里有个细微的小Bug：headersbecause。这是两个词，应该空开的 :-)
8.更名对 Bigfile 表空间一样有效。

9.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
10.参考信息
Oracle Database Administrator's Guide 10g Release 1 (10.1) Part Number B10739-01 ( Note 62294.1 )