rman恢复部分数据文件的方法

继上一篇rman恢复部分表空间 后考虑是否能恢复部分数据文件喃？带着这个问题做了以下测试，该测试只去证明了能否恢复部分数据文件，没有去考虑操作的规范性。
接着上一篇文章中的实验环境继续操作:
1、为测试表所在表空间添加新的数据文件

SQL> 
SQL> alter tablespace test1 add datafile '/oradata/ora11g/test02.dbf' size 100m;
Tablespace altered.
SQL> 
SQL> 
SQL> select file_id,file_name,tablespace_name from dba_data_files
  2  /
   FILE_ID FILE_NAME                                          TABLESPACE_NAME
---------- -------------------------------------------------- ------------------------------
         4 /oradata/ora11g/users01.dbf                        USERS
         3 /oradata/ora11g/undotbs01.dbf                      UNDOTBS1
         2 /oradata/ora11g/sysaux01.dbf                       SYSAUX
         1 /oradata/ora11g/system01.dbf                       SYSTEM
         5 /oradata/ora11g/example01.dbf                      EXAMPLE
         6 /oradata/ora11g/test01.dbf                         TEST1
         7 /oradata/ora11g/test21.dbf                         TEST2
         8 /oradata/ora11g/test31.dbf                         TEST3
         9 /oradata/ora11g/test02.dbf                         TEST1
9 rows selected.
SQL> 

SQL> set pages 200
SQL> select owner,segment_name,extent_id,file_id from dba_extents where owner='HCN';
OWNER SEGMENT_NAME EXTENT_ID FILE_ID
------------------------------ --------------------------------------------------------------------------------- ---------- ----------
HCN TEST1 0 6
HCN TEST1 1 6
HCN TEST1 2 6
HCN TEST1 3 6
HCN TEST1 4 6
HCN TEST1 5 6
HCN TEST1 6 6
HCN TEST1 7 6
HCN TEST1 8 6
HCN TEST1 9 6
HCN TEST1 10 6
HCN TEST1 11 6
HCN TEST1 12 6
HCN TEST1 13 6
HCN TEST1 14 6
HCN TEST1 15 6
HCN TEST1 16 6
HCN TEST1 17 6
HCN TEST1 18 6
HCN TEST1 19 6
HCN TEST1 20 6
HCN TEST1 21 6
HCN TEST1 22 6
HCN TEST1 23 6
HCN TEST1 24 6
25 rows selected.
SQL> 

测试表test1的所有数据均在数据文件test01.dbf中
2、重新全备数据文件、控制文件以及归档（方法可以参考上一篇文章）
3、异机恢复，通过pfile启动数据库到nomount状态，并恢复控制文件，启动数据库到mount状态，方法参考上一篇文章
4、恢复需要的数据文件

RMAN> 
RMAN> restore datafile 1,2,3,4,5,6,7,8;
Starting restore at 21-MAR-16
Starting implicit crosscheck backup at 21-MAR-16
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=63 device type=DISK
Crosschecked 2 objects
Finished implicit crosscheck backup at 21-MAR-16
Starting implicit crosscheck copy at 21-MAR-16
using channel ORA_DISK_1
Finished implicit crosscheck copy at 21-MAR-16
searching for all files in the recovery area
cataloging files...
no files cataloged
using channel ORA_DISK_1
channel ORA_DISK_1: starting datafile backup set restore
channel ORA_DISK_1: specifying datafile(s) to restore from backup set
channel ORA_DISK_1: restoring datafile 00001 to /oradata/ora11g/system01.dbf
channel ORA_DISK_1: restoring datafile 00002 to /oradata/ora11g/sysaux01.dbf
channel ORA_DISK_1: restoring datafile 00003 to /oradata/ora11g/undotbs01.dbf
channel ORA_DISK_1: restoring datafile 00004 to /oradata/ora11g/users01.dbf
channel ORA_DISK_1: restoring datafile 00005 to /oradata/ora11g/example01.dbf
channel ORA_DISK_1: restoring datafile 00006 to /oradata/ora11g/test01.dbf
channel ORA_DISK_1: restoring datafile 00007 to /oradata/ora11g/test21.dbf
channel ORA_DISK_1: restoring datafile 00008 to /oradata/ora11g/test31.dbf
channel ORA_DISK_1: reading from backup piece /oradata/rmanbak/full_bkl_07r12qej17.rmn
channel ORA_DISK_1: piece handle=/oradata/rmanbak/full_bkl_07r12qej17.rmn tag=TAG20160321T231427
channel ORA_DISK_1: restored backup piece 1
channel ORA_DISK_1: restore complete, elapsed time: 00:00:15
Finished restore at 21-MAR-16
RMAN> 
RMAN> recover database skip tablespace test1;
Starting recover at 21-MAR-16
using channel ORA_DISK_1
Executing: alter database datafile 6 offline
Executing: alter database datafile 9 offline
starting media recovery
unable to find archived log
archived log thread=1 sequence=14
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of recover command at 03/21/2016 23:20:32
RMAN-06054: media recovery requesting unknown archived log for thread 1 with sequence 14 and starting SCN of 1005801
RMAN> 
RMAN> 
RMAN> alter database open resetlogs;
database opened
RMAN> 
SQL> 
SQL> select file#,status,name from v$datafile;
     FILE# STATUS  NAME
---------- ------- ------------------------------------------------------------
         1 SYSTEM  /oradata/ora11g/system01.dbf
         2 ONLINE  /oradata/ora11g/sysaux01.dbf
         3 ONLINE  /oradata/ora11g/undotbs01.dbf
         4 ONLINE  /oradata/ora11g/users01.dbf
         5 ONLINE  /oradata/ora11g/example01.dbf
         6 OFFLINE /oradata/ora11g/test01.dbf
         7 ONLINE  /oradata/ora11g/test21.dbf
         8 ONLINE  /oradata/ora11g/test31.dbf
         9 OFFLINE /oradata/ora11g/test02.dbf
9 rows selected.
SQL> 
/* 恢复表数据所在的数据文件file_id=6的数据文件 */
[oracle@orl5 ~]$ 
[oracle@orl5 ~]$ rman target /
Recovery Manager: Release 11.2.0.4.0 - Production on Mon Mar 21 23:24:09 2016
Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.
connected to target database: ORA11G (DBID=8338623, not open)
RMAN> restore datafile 6;
Starting restore at 21-MAR-16
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=63 device type=DISK
skipping datafile 6; already restored to file /oradata/ora11g/test01.dbf
restore not done; all files read only, offline, or already restored
Finished restore at 21-MAR-16
RMAN> recover datafile 6;
Starting recover at 21-MAR-16
using channel ORA_DISK_1
starting media recovery
media recovery complete, elapsed time: 00:00:00
Finished recover at 21-MAR-16
RMAN> 
RMAN> alter database open;
database opened
RMAN> 
SQL> 
SQL> alter database datafile 6 online;
Database altered.
SQL> 
SQL> 
/* 验证数据 */
SQL> 
SQL> select count(*) from hcn.test1;
  COUNT(*)
----------
     86956
SQL>

实验证明如果一个表空间中存在多个数据文件，其实是可以只恢复部分数据文件的，不需要的数据文件可以继续保持offline的状态。