步骤如下：
1. 启动数据库到mount状态
2. 使该数据文件处于offline状态 （ alter database datafile 4 offline）
3. restore数据文件（restore datafile 4 ）
4. recover数据文件（restore datafile 4 ）
5. 合该数据文件处于online状态（ alter database datafile 4 online ）
重启后发现报错，先offline，再打开数据库，然后在用rman restore和recover，online数据文件。顺序为52436 D答案
sys@TEST1107> startup
ORACLE instance started.
Total System Global Area 1252663296 bytes
Fixed Size 2227944 bytes
Variable Size 1006633240 bytes
Database Buffers 234881024 bytes
Redo Buffers 8921088 bytes
Database mounted.
ORA-01157: cannot identify/lock data file 4 - see DBWR trace file
ORA-01110: data file 4: '/u01/app/oracle/oradata/test1107/users01.dbf' （可以看出数据文件号为4的数据文件损坏）
sys@TEST1107> alter database datafile 4 offline;
Database altered.
sys@TEST1107> alter database open;
Database altered.
sys@TEST1107> select * from scott.dept;
select * from scott.dept
*
ERROR at line 1:
ORA-00376: file 4 cannot be read at this time
ORA-01110: data file 4: '/u01/app/oracle/oradata/test1107/users01.dbf'
[oracle@rtest ~]$ rman target /
Recovery Manager: Release 11.2.0.3.0 - Production on Tue Dec 24 10:06:13 2013
Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights reserved.
connected to target database: TEST1107 (DBID=2336818266)
RMAN> restore datafile 4;
Starting restore at 24-DEC-13
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=192 device type=DISK
allocated channel: ORA_DISK_2
channel ORA_DISK_2: SID=221 device type=DISK
allocated channel: ORA_DISK_3
channel ORA_DISK_3: SID=6 device type=DISK
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 00004 to /u01/app/oracle/oradata/test1107/users01.dbf
channel ORA_DISK_1: reading from backup piece /u01/app/oracle/fast_recovery_area/TEST1107/backupset/2013_12_24/o1_mf_nnndf_TAG20131224T090841_9cm5cf76_.bkp
channel ORA_DISK_1: piece handle=/u01/app/oracle/fast_recovery_area/TEST1107/backupset/2013_12_24/o1_mf_nnndf_TAG20131224T090841_9cm5cf76_.bkp tag=TAG20131224T090841
channel ORA_DISK_1: restored backup piece 1
channel ORA_DISK_1: restore complete, elapsed time: 00:00:04
Finished restore at 24-DEC-13
RMAN> recover datafile 4;
Starting recover at 24-DEC-13
using channel ORA_DISK_1
using channel ORA_DISK_2
using channel ORA_DISK_3
starting media recovery
archived log for thread 1 with sequence 437 is already on disk as file /u01/rmanbak/d1/1_437_830778999.dbf
archived log for thread 1 with sequence 438 is already on disk as file /u01/rmanbak/d1/1_438_830778999.dbf
archived log for thread 1 with sequence 439 is already on disk as file /u01/rmanbak/d1/1_439_830778999.dbf
archived log file name=/u01/rmanbak/d1/1_437_830778999.dbf thread=1 sequence=437
media recovery complete, elapsed time: 00:00:02
Finished recover at 24-DEC-13
RMAN> sql 'alter database datafile 4 online';
sql statement: alter database datafile 4 online
sys@TEST1107> select * from scott.dept;
DEPTNO DNAME LOC
---------- -------------- -------------
10 ACCOUNTING NEW YORK
20 RESEARCH DALLAS
30 SALES CHICAGO
40 OPERATIONS BOSTON