如果要快速移动数据文件，对业务的影响最小，可以使用rman的backup as copy功能，先拷贝文件到
需要移动的目录，然后再追加增量变化，再利用增量备份来恢复copy文件，再切换数据文件。

做一个例子来说明整个过程:

SQL> select * from v$version where rownum<=1;

BANNER

--------------------------------------------------------------------------------

Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production

RMAN> report schema ;

using target database control file instead of recovery catalog

Report of database schema for database with db_unique_name TEST

List of Permanent Datafiles

===========================

File Size(MB) Tablespace           RB segs Datafile Name

---- -------- -------------------- ------- ------------------------

1    770      SYSTEM               ***     /u01/app/oracle11g/oradata/test/system01.dbf

2    840      SYSAUX               ***     /u01/app/oracle11g/oradata/test/sysaux01.dbf

3    1024     UNDOTBS1             ***     /u01/app/oracle11g/oradata/test/undotbs01.dbf

4    656      USERS                ***     /u01/app/oracle11g/oradata/test/users01.dbf

5    100      EXAMPLE              ***     /u01/app/oracle11g/oradata/test/example01.dbf

6    64       RMAN                 ***     /u01/app/oracle11g/oradata/test/rman01.dbf

7    64       TOOLS                ***     /u01/app/oracle11g/oradata/test/tools01.dbf

8    64       TEST                 ***     /u01/app/oracle11g/oradata/test/test01.dbf

List of Temporary Files

=======================

File Size(MB) Tablespace           Maxsize(MB) Tempfile Name

---- -------- -------------------- ----------- --------------------

1    339      TEMP                 339         /u01/app/oracle11g/oradata/test/temp01.dbf

RMAN> backup as copy datafile 8 format '/data/testtest/test01.dbf';

Starting backup at 2013-01-04 11:36:47

allocated channel: ORA_DISK_1

channel ORA_DISK_1: SID=191 device type=DISK

channel ORA_DISK_1: starting datafile copy

input datafile file number=00008 name=/u01/app/oracle11g/oradata/test/test01.dbf

output file name=/data/testtest/test01.dbf tag=TAG20130104T113649 RECID=1 STAMP=803821013

channel ORA_DISK_1: datafile copy complete, elapsed time: 00:00:07

Finished backup at 2013-01-04 11:36:56

RMAN> list copy of datafile 8;

List of Datafile Copies

=======================

Key     File S Completion Time     Ckp SCN    Ckp Time

------- ---- - ------------------- ---------- -------------------

1       8    A 2013-01-04 11:36:53 3221576548 2013-01-04 11:36:49

        Name: /data/testtest/test01.dbf

        Tag: TAG20130104T113649

--注意显示的Ckp SCN=3221576548.

--在test表空间上建立一些表。

create table t2 tablespace test as select * from dba_objects;

RMAN> backup incremental from scn 3221576548 datafile 8 format '/data/testtest/%U';

Starting backup at 2013-01-04 11:42:17

using channel ORA_DISK_1

backup will be obsolete on date 2013-01-11 11:42:18

archived logs will not be kept or backed up

channel ORA_DISK_1: starting full datafile backup set

channel ORA_DISK_1: specifying datafile(s) in backup set

input datafile file number=00008 name=/u01/app/oracle11g/oradata/test/test01.dbf

channel ORA_DISK_1: starting piece 1 at 2013-01-04 11:42:18

channel ORA_DISK_1: finished piece 1 at 2013-01-04 11:42:19

piece handle=/data/testtest/0bnuiloq_1_1 tag=TAG20130104T114217 comment=NONE

channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01

using channel ORA_DISK_1

backup will be obsolete on date 2013-01-11 11:42:20

archived logs will not be kept or backed up

channel ORA_DISK_1: starting full datafile backup set

channel ORA_DISK_1: specifying datafile(s) in backup set

including current control file in backup set

channel ORA_DISK_1: starting piece 1 at 2013-01-04 11:42:22

channel ORA_DISK_1: finished piece 1 at 2013-01-04 11:42:23

piece handle=/data/testtest/0cnuilot_1_1 tag=TAG20130104T114217 comment=NONE

channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01

Finished backup at 2013-01-04 11:42:23

RMAN> recover copy of datafile 8;

Starting recover at 2013-01-04 11:43:16

using channel ORA_DISK_1

channel ORA_DISK_1: starting incremental datafile backup set restore

channel ORA_DISK_1: specifying datafile copies to recover

recovering datafile copy file number=00008 name=/data/testtest/test01.dbf

channel ORA_DISK_1: reading from backup piece /data/testtest/0bnuiloq_1_1

channel ORA_DISK_1: piece handle=/data/testtest/0bnuiloq_1_1 tag=TAG20130104T114217

channel ORA_DISK_1: restored backup piece 1

channel ORA_DISK_1: restore complete, elapsed time: 00:00:01

Finished recover at 2013-01-04 11:43:20

RMAN> list copy of datafile 8;

List of Datafile Copies

=======================

Key     File S Completion Time     Ckp SCN    Ckp Time

------- ---- - ------------------- ---------- -------------------

2       8    A 2013-01-04 11:43:19 3221577302 2013-01-04 11:42:18

        Name: /data/testtest/test01.dbf

        Tag: TAG20130104T113649

--可以发现Ckp SCN=3221577302.

--再执行如下脚本，实现切换。

run

{

     sql 'alter database datafile 8 offline';

     switch datafile 8 to datafilecopy '/data/testtest/test01.dbf';

     recover datafile 8;

     sql 'alter database datafile 8 online';

}

sql statement: alter database datafile 8 offline

datafile 8 switched to datafile copy

input datafile copy RECID=2 STAMP=803821399 file name=/data/testtest/test01.dbf

Starting recover at 2013-01-04 11:46:38

using channel ORA_DISK_1

starting media recovery

media recovery complete, elapsed time: 00:00:00

Finished recover at 2013-01-04 11:46:42

sql statement: alter database datafile 8 online

RMAN> report schema ;

Report of database schema for database with db_unique_name TEST

List of Permanent Datafiles

===========================

File Size(MB) Tablespace           RB segs Datafile Name

---- -------- -------------------- ------- ------------------------

1    770      SYSTEM               ***     /u01/app/oracle11g/oradata/test/system01.dbf

2    840      SYSAUX               ***     /u01/app/oracle11g/oradata/test/sysaux01.dbf

3    1024     UNDOTBS1             ***     /u01/app/oracle11g/oradata/test/undotbs01.dbf

4    656      USERS                ***     /u01/app/oracle11g/oradata/test/users01.dbf

5    100      EXAMPLE              ***     /u01/app/oracle11g/oradata/test/example01.dbf

6    64       RMAN                 ***     /u01/app/oracle11g/oradata/test/rman01.dbf

7    64       TOOLS                ***     /u01/app/oracle11g/oradata/test/tools01.dbf

8    64       TEST                 ***     /data/testtest/test01.dbf

List of Temporary Files

=======================

File Size(MB) Tablespace           Maxsize(MB) Tempfile Name

---- -------- -------------------- ----------- --------------------

1    339      TEMP                 339         /u01/app/oracle11g/oradata/test/temp01.dbf

--可以发现已经移动了数据文件。这样对业务影响最小。

http://blog.itpub.net/267265/viewspace-752054/