故障现象：
data guard归档出现gap，悲剧的是丢失的归档在主库上被rman备份时删除了，丢失的归档大约有20几个，数据库大小约2T，如果重建DG将非常耗时间，因此决定利用增量备份的方式恢复DG，主要步骤如下：
1.备份备库spfile文件
SQL> create pfile='/home/ora/pfileRdg.ora' from spfile;

2、查看当前备库scn
SQL> select to_char(current_scn) from v$database;

TO_CHAR(CURRENT_SCN)
----------------------------------------
19652214434
3、查看缺失的archivelog
SQL> select * from v$archive_gap;

   THREAD# LOW_SEQUENCE# HIGH_SEQUENCE#
---------- ------------- --------------
         1        160163         160170
         2        151303         151309
、在主库执增量备份

[ora@jzhRAC1 ~]$ rman target /

Recovery Manager: Release 10.2.0.4.0 - Production on Sat May 23 18:10:52 2015

Copyright (c) 1982, 2007, Oracle.  All rights reserved.

connected to target database: JZH (DBID=2072634265)
RMAN> run
2> {
3> allocate channel d1 type disk;
4> allocate channel d2 type disk;
5> allocate channel d3 type disk;
6> backup as compressed backupset incremental from SCN 19652214434 database format '/home/ora/full_db_%d_%T_%s.bak' include current controlfile for standby 

filesperset=5 tag 'FOR STANDBY';
7> release channel d1;
8> release channel d2;
9> release channel d3;
10> }
channel d1: backup set complete, elapsed time: 00:00:35
channel d1: starting compressed full datafile backupset
channel d1: specifying datafile(s) in backupset
input datafile fno=00124 name=/oradata/JZH/TP_CTEST15.ORA
input datafile fno=00186 name=/oradata/JZH/TP_LEARNING01.ORA
input datafile fno=00187 name=/oradata/JZH/TP_LEARNING02.ORA
input datafile fno=00188 name=/oradata/JZH/TP_LEARNING03.ORA
input datafile fno=00191 name=/oradata/JZH/TP_LEARNING06.ORA
channel d1: starting piece 1 at 23-MAY-15
channel d3: finished piece 1 at 23-MAY-15
piece handle=/home/ora/full_db_JZH_20150523_232604.bak tag=FOR STANDBY comment=NONE
channel d3: backup set complete, elapsed time: 00:00:36
channel d3: starting compressed full datafile backupset
channel d3: specifying datafile(s) in backupset
input datafile fno=00192 name=/oradata/JZH/TP_LEARNING07.ORA
input datafile fno=00239 name=/oradata/JZH/TP_LEARNING08.ORA
input datafile fno=00250 name=/oradata/JZH/TP_LEARNING09.ORA
input datafile fno=00261 name=/oradata/JZH/TP_CTEST16.ORA
input datafile fno=00267 name=/oradata/JZH/TP_LEARNING10.ORA
channel d3: starting piece 1 at 23-MAY-15
channel d2: finished piece 1 at 23-MAY-15
piece handle=/home/ora/full_db_JZH_20150523_232602.bak tag=FOR STANDBY comment=NONE
channel d2: backup set complete, elapsed time: 00:01:08
channel d2: starting compressed full datafile backupset
channel d2: specifying datafile(s) in backupset
input datafile fno=00272 name=/oradata/JZH/TP_CTEST17.ORA
input datafile fno=00284 name=/oradata/JZH/TP_CTEST18.ORA
input datafile fno=00288 name=/oradata/JZH/TP_LEARNING11.ORA
input datafile fno=00296 name=/oradata/JZH/TP_CTEST19.ORA
input datafile fno=00313 name=/oradata/JZH/TP_LEARNING12.ORA
channel d2: starting piece 1 at 23-MAY-15
channel d1: finished piece 1 at 23-MAY-15
piece handle=/home/ora/full_db_JZH_20150523_232606.bak tag=FOR STANDBY comment=NONE
channel d1: backup set complete, elapsed time: 00:00:32
channel d1: starting compressed full datafile backupset
channel d1: specifying datafile(s) in backupset
input datafile fno=00338 name=/oradata/JZH/TP_LEARNING15.ORA
input datafile fno=00342 name=/oradata/JZH/TP_CTEST22.ORA
channel d1: starting piece 1 at 23-MAY-15
channel d3: finished piece 1 at 23-MAY-15
piece handle=/home/ora/full_db_JZH_20150523_232607.bak tag=FOR STANDBY comment=NONE
channel d3: backup set complete, elapsed time: 00:00:32
channel d3: starting compressed full datafile backupset
channel d3: specifying datafile(s) in backupset
including standby control file in backupset
channel d3: starting piece 1 at 23-MAY-15
channel d1: finished piece 1 at 23-MAY-15
piece handle=/home/ora/full_db_JZH_20150523_232609.bak tag=FOR STANDBY comment=NONE
channel d1: backup set complete, elapsed time: 00:00:06
channel d1: starting compressed full datafile backupset
channel d1: specifying datafile(s) in backupset
including current SPFILE in backupset
channel d1: starting piece 1 at 23-MAY-15
channel d3: finished piece 1 at 23-MAY-15
piece handle=/home/ora/full_db_JZH_20150523_232610.bak tag=FOR STANDBY comment=NONE
channel d3: backup set complete, elapsed time: 00:00:08
channel d1: finished piece 1 at 23-MAY-15
piece handle=/home/ora/full_db_JZH_20150523_232611.bak tag=FOR STANDBY comment=NONE
channel d1: backup set complete, elapsed time: 00:00:02
channel d2: finished piece 1 at 23-MAY-15
piece handle=/home/ora/full_db_JZH_20150523_232608.bak tag=FOR STANDBY comment=NONE
channel d2: backup set complete, elapsed time: 00:00:32
Finished backup at 23-MAY-15

released channel: d1

released channel: d2

released channel: d3

5、将备份传至备库
scp full_db_JZH_20150523_*.bak 192.168.110.115:~/20150523_recover/ 
6、恢复备库
[ora@jzhDG ~]$ rman target /

Recovery Manager: Release 10.2.0.4.0 - Production on Sat May 23 20:17:59 2015

Copyright (c) 1982, 2007, Oracle.  All rights reserved.

connected to target database: JZH (DBID=2072634265, not open)

RMAN> catalog start with '/home/ora/20150523_recover';

[ora@jzhDG ~]$ rman target /

Recovery Manager: Release 10.2.0.4.0 - Production on Sat May 23 20:25:44 2015

Copyright (c) 1982, 2007, Oracle.  All rights reserved.

connected to target database: JZH (DBID=2072634265, not open)

RMAN> run
2> {
3> allocate channel d1 type disk;
4> allocate channel d2 type disk;
5> allocate channel d3 type disk;
6> restore standby controlfile to '/home/ora/control01.ctl';
7> recover database noredo;
8> release channel d1;
9> release channel d2;
10> release channel d3;
11> }
7、关闭备库，将恢复出来的control01.ctl覆盖备库控制文件
[ora@jzhDG ~]$ cp control01.ctl /oradata/JZH/standby.ctl
8、启动备库至mount状态
SQL> startup mount
ORACLE instance started.
Total System Global Area 1795162112 bytes
Fixed Size                  2084648 bytes
Variable Size             301990104 bytes
Database Buffers         1476395008 bytes
Redo Buffers               14692352 bytes
Database mounted.
9、查看gap
SQL> select * from v$archive_gap;
no rows selected
10、开启备库recover模式
SQL> recover managed standby database disconnect from session;
Media recovery complete.
11、查看日志，正在恢复
Sat May 23 21:17:53 2015
Media Recovery Log /oradata/standby_arch/1_161210_706979804.log
Sat May 23 21:18:15 2015
Media Recovery Log /oradata/standby_arch/1_161211_706979804.log
Media Recovery Log /oradata/standby_arch/2_152328_706979804.log
Sat May 23 21:19:14 2015
Media Recovery Log /oradata/standby_arch/1_161212_706979804.log
Sat May 23 21:20:06 2015
Media Recovery Log /oradata/standby_arch/2_152329_706979804.log
Sat May 23 21:20:29 2015
Media Recovery Log /oradata/standby_arch/1_161213_706979804.log
Media Recovery Log /oradata/standby_arch/2_152330_706979804.log
Sat May 23 21:20:50 2015
Media Recovery Log /oradata/standby_arch/2_152331_706979804.log
Media Recovery Log /oradata/standby_arch/1_161214_706979804.log
Sat May 23 21:21:10 2015
Media Recovery Log /oradata/standby_arch/1_161215_706979804.log
Sat May 23 21:21:20 2015
Media Recovery Log /oradata/standby_arch/2_152332_706979804.log
Sat May 23 21:21:31 2015
Media Recovery Log /oradata/standby_arch/1_161216_706979804.log
Sat May 23 21:21:41 2015
Media Recovery Log /oradata/standby_arch/2_152333_706979804.log
Sat May 23 21:21:53 2015
Media Recovery Waiting for thread 1 sequence 161217