教你轻松掌握重建UNDO TABLESPACE的好方法

来源：赛迪网    作者：10903

问题：我在同一平台下迁移时因为空间问题，不打算要现在的UNDO文件了，我打算重建一个。请问有什么具体的解决方法吗？（注释：目前拥有一个冷备份）

解答：如果你目前拥有一个冷备份的话，我可以在下文中介绍一个不用隐含参数的好方法。

具体示例如下：

C:\Documents and Settings\gqgai>sqlplus "/ as sysdba"

SQL*Plus: Release 9.2.0.6.0 - Production on Fri Mar 4 20:55:59 2005

Copyright (c) 1982, 2002, Oracle Corporation.  All rights reserved.


Connected to:
Oracle9i Enterprise Edition Release 9.2.0.6.0 - Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.6.0 - Production

20:55:59 SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
20:56:14 SQL> startup
ORACLE instance started.

Total System Global Area   59842188 bytes
Fixed Size                   454284 bytes
Variable Size              33554432 bytes
Database Buffers           25165824 bytes
Redo Buffers                 667648 bytes
Database mounted.
ORA-01157: cannot identify/lock data file 2 - see DBWR trace file
ORA-01110: data file 2: 'D:\ORADATA\EYGLE\UNDOTBS01.DBF'


20:59:28 SQL> alter database datafile 'D:\ORADATA\EYGLE\UNDOTBS01.DBF' offline drop;

Database altered.

Elapsed: 00:00:00.00
20:59:34 SQL> alter database open;

Database altered.

Elapsed: 00:00:02.04
20:59:40 SQL> select name from v$datafile;

NAME
-------------------------------------------------------
D:\ORADATA\EYGLE\SYSTEM01.DBF
D:\ORADATA\EYGLE\UNDOTBS01.DBF
D:\ORADATA\EYGLE\PERFSTAT01.DBF
D:\ORADATA\EYGLE\EYGLE.DBF

21:00:55 SQL> create undo tablespace undotbs2
21:01:03   2  datafile 'd:\oradata\eygle\undotbs2.dbf' size 10M;

Tablespace created.

Elapsed: 00:00:02.02

21:06:29 SQL> ALTER SYSTEM SET undo_tablespace='UNDOTBS2' ;

System altered.

Elapsed: 00:00:00.01