参考自：
HOW TO RECOVER OFFLINE DROPPED DATAFILE IN ARCHIVELOG MODE (文档 ID 286355.1)
如下的实验基于Oracle 11.2.0.4 linux x86-64bit完成
[oracle@rhel63single u02]$ sqlplus / as sysdba
SQL*Plus: Release 11.2.0.4.0 Production on Sun Feb 15 20:33:17 2015
Copyright (c) 1982, 2013, Oracle. All rights reserved.
Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
SQL> archive log list;
Database log mode Archive Mode
Automatic archival Enabled
Archive destination /u02/arch
Oldest online log sequence 126
Next log sequence to archive 128
Current log sequence 128
SQL> select file_id from dba_data_files;
FILE_ID
----------
4
3
2
1
5
6
7
8
9
10
11
11 rows selected.
SQL> select name from v$dbfile;
NAME
--------------------------------------------------------------------------------
/u01/app/oracle/oradata/test/users01.dbf
/u01/app/oracle/oradata/test/undotbs01.dbf
/u01/app/oracle/oradata/test/sysaux01.dbf
/u01/app/oracle/oradata/test/system01.dbf
/u01/app/oracle/oradata/test/ten01.dbf
/u01/app/oracle/oradata/test/tb_test_01.dbf
/u01/app/oracle/oradata/test/ts1.dbf
/u01/app/oracle/oradata/test/ts2.dbf
/u01/app/oracle/oradata/test/test01.dbf
/u01/app/oracle/oradata/test/test_uni_sz_2m_01.dbf
/u01/app/oracle/oradata/test/test_uni_sz_1m_01.dbf
11 rows selected.
SQL> set lines 290
SQL> col file_name format a60
SQL> select FILE_NAME,file_Id from v$dbfile;
FILE_NAME FILE_ID
------------------------------------------------------------ ----------
/u01/app/oracle/oradata/test/users01.dbf 4
/u01/app/oracle/oradata/test/undotbs01.dbf 3
/u01/app/oracle/oradata/test/sysaux01.dbf 2
/u01/app/oracle/oradata/test/system01.dbf 1
/u01/app/oracle/oradata/test/ten01.dbf 5
/u01/app/oracle/oradata/test/tb_test_01.dbf 6
/u01/app/oracle/oradata/test/ts1.dbf 7
/u01/app/oracle/oradata/test/ts2.dbf 8
/u01/app/oracle/oradata/test/test01.dbf 9
/u01/app/oracle/oradata/test/test_uni_sz_2m_01.dbf 10
/u01/app/oracle/oradata/test/test_uni_sz_1m_01.dbf 11
11 rows selected.
SQL> alter database datafile 9 offline drop;
Database altered.
SQL> select file#, status from v$datafile where file#='9';
FILE# STATUS
---------- -------
9 RECOVER
SQL> select file#, status from v$datafile_header where file#='9';
FILE# STATUS
---------- -------
9 OFFLINE
SQL> alter system switch logfile ;
System altered.
SQL> /
System altered.
SQL> /
/
/
System altered.
SQL>
System altered.
SQL>
System altered.
SQL> SQL>
SQL>
SQL> /
System altered.
SQL>
SQL>
SQL> archive log list;
Database log mode Archive Mode
Automatic archival Enabled
Archive destination /u02/arch
Oldest online log sequence 132
Next log sequence to archive 134
Current log sequence 134
SQL> recover datafile 9;
ORA-00279: change 3155176 generated at 02/15/2015 20:34:05 needed for thread 1
ORA-00289: suggestion : /u02/arch/1_128_807882551.dbf
ORA-00280: change 3155176 for thread 1 is in sequence #128
Specify log: {<RET>=suggested | filename | AUTO | CANCEL}
auto --------------->敲入auto
Log applied.
Media recovery complete.
SQL> select * from v$log;
GROUP# THREAD# SEQUENCE# BYTES BLOCKSIZE MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIM NEXT_CHANGE# NEXT_TIME
---------- ---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- --------- ------------ ---------
1 1 133 52428800 512 1 YES INACTIVE 3155684 15-FEB-15 3155687 15-FEB-15
2 1 134 52428800 512 1 NO CURRENT 3155687 15-FEB-15 2.8147E+14
3 1 132 52428800 512 1 YES INACTIVE 3155681 15-FEB-15 3155684 15-FEB-15
SQL> select file#,status from v$datafile where file#=9;
FILE# STATUS
---------- -------
9 OFFLINE
SQL> select file#,status from v$datafile_header where file#=9;
FILE# STATUS
---------- -------
9 OFFLINE
SQL> alter database datafile 9 online;
Database altered.
SQL> select file#,status from v$datafile where file#=9;
FILE# STATUS
---------- -------
9 ONLINE
SQL>
知识点：
1.The only case in which the offline dropped datafile can not be online is when you have added to many datafiles in the database after offline drop
2.在非归档模式下，为了让一个datafile 变成offline，必须带drop关键字。
drop关键字不会把datafile从database 中 remove掉。
To do that, you must drop the tablespace in which the datafile resides. Until you do so, the datafile remains in the data dictionary with the status RECOVER or OFFLINE.
若是database处于归档模式，Oracle会忽略掉drop 关键字.