主库查询最小scn 信息：
SQL> col current_scn for 999999999999999
SQL> SELECT CURRENT_SCN FROM V$DATABASE;
select min(fhscn) from x$kcvfh;
select min(f.fhscn) from x$kcvfh f, v$datafile d
where f.hxfil =d.file#
and d.enabled != 'READ ONLY' ;
CURRENT_SCN
----------------
12614205226673
MIN(FHSCN)
----------------
12614205076072
MIN(F.FHSCN)
----------------
12614205076072
+++++++++++++++++++++++++++++++++++++++++++++++=
1.----备库取消归档应用
ALTER DATABASE RECOVER MANAGED STANDBY DATABASE CANCEL;
2.----备库确定 lowest scn
col current_scn for 99999999999999
SELECT CURRENT_SCN FROM V$DATABASE;
select min(fhscn) from x$kcvfh;
select min(f.fhscn) from x$kcvfh f, v$datafile d
where f.hxfil =d.file#
and d.enabled != 'READ ONLY' ;
取上述查询中的最小值
SQL> col current_scn for 999999999999999999
SQL> SELECT CURRENT_SCN FROM V$DATABASE;
CURRENT_SCN
-------------------
12611050666604
SQL> select min(fhscn) from x$kcvfh;
MIN(FHSCN)
----------------
12611050666605
SQL> select min(f.fhscn) from x$kcvfh f, v$datafile d
where f.hxfil =d.file#
and d.enabled != 'READ ONLY' ; 2 3
MIN(F.FHSCN)
----------------
12611050666605
3.-----on primary db 端依据第2步中获取的最小scn 来进行增量备份
BACKUP INCREMENTAL FROM SCN 12611050666604 DATABASE FORMAT '/lixora/ForStandby_%U' tag 'FORSTANDBY';
4.-----拷贝备份到 备库
$scp ForStandby_07pqprm4_1_1 192.168.0.10:/tmp
5.----on standby db 在备库端注冊备份片，注意用户属主。权限
RMAN> CATALOG START WITH '/lixora/ForStandby';
6.----运行恢复
RMAN> RECOVER DATABASE NOREDO;
7.-----on primary db 生成新的standby 控制文件
RMAN> BACKUP CURRENT CONTROLFILE FOR STANDBY FORMAT '/lixora/ForStandbyCTRL.bck';
8.----把主库端生成的standby 控制文件复制到备库，注意用户属主。权限
RMAN> BACKUP CURRENT CONTROLFILE FOR STANDBY FORMAT '/lixora/ForStandbyCTRL.bck';
scp /lixora/ForStandbyCTRL.bck 192.168.0.10:/tmp
9.------备份备库数据文件信息，用于在恢复新的standby 控制文件后比对
spool datafile_names_step8.txt
set lines 200
col name format a60
select file#, name from v$datafile order by file# ;
spool off
10.------on standby Db 恢复新的standby 控制文件
RMAN> SHUTDOWN IMMEDIATE ;
RMAN> STARTUP NOMOUNT;
RMAN> RESTORE STANDBY CONTROLFILE FROM '/tmp/ForStandbyCTRL.bck';
11.-----更新控制文件里的数据文件信息
使新的standby 控制文件生效
RMAN> SHUTDOWN;
RMAN> STARTUP MOUNT;
CATALOG START WITH '+DATA/zhglptdg/datafile/';
12.------on primary db。
确保在备库发生日志gap 后，主库没有加入过新的数据文件。
SELECT FILE#, NAME FROM V$DATAFILE WHERE CREATION_CHANGE# > 12611050666604；
假设有记录。则不能进行witch 操作，能够參考一下文档来恢复：
rman 增量恢复 dg gap后 主库加入新数据文件
Note 1531031.1 Steps to perform for Rolling forward a standby database using RMAN incremental backup when datafile is added to primary
13.-----重命名数据文件
RMAN> SWITCH DATABASE TO COPY;
14.-----再次确认在恢复增量备份片后主库和备库scn 差距没有太大
SQL> col current_scn for 99999999999999
SELECT CURRENT_SCN FROM V$DATABASE;
select min(fhscn) from x$kcvfh;
select min(f.fhscn) from x$kcvfh f, v$datafile d
where f.hxfil =d.file#
and d.enabled != 'READ ONLY' ;
CURRENT_SCN
---------------
12614205662375
MIN(FHSCN)
----------------
12614205076072
MIN(F.FHSCN)
----------------
12614205076072
15.------ On standby database, 清理standby 日志组
select * from v$standby_log;
SQL> ALTER DATABASE CLEAR LOGFILE GROUP 1;
SQL> ALTER DATABASE CLEAR LOGFILE GROUP 2;
SQL> ALTER DATABASE CLEAR LOGFILE GROUP 3;
16.------启动redo data apply
SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT;
假设遇到一些因为设置 nologgling 而导致部分数据丢失，能够安装下述方法来进行恢复
To resolve NOLOGGING operations only, see Note 958181.1.
In addition to this information, see the online documentation:
10.2: http://download.oracle.com/docs/cd/B19306_01/server.102/b14239/scenarios.htm#CIHIAADC
11.1: http://download.oracle.com/docs/cd/B28359_01/server.111/b28294/rman.htm#SBYDB00759
11.2: http://download.oracle.com/docs/cd/E11882_01/server.112/e17022/rman.htm#CIHIAADC
后记
假设要启用实时应用，须要在备库加入standby redo log，大小应和主库一样。且比主库多一组。
ALTER DATABASE add standby LOGFILE GROUP 6 size 500M;
ALTER DATABASE add standby LOGFILE GROUP 7 size 500M;
ALTER DATABASE add standby LOGFILE GROUP 8 size 500M;
ALTER DATABASE add standby LOGFILE GROUP 9 size 500M;
启用命令：
ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT LOGFILE;
详细内容參见：
oracle 10g standby database 实时应用 redo 数据
怎样确保dg 已经正常，后台日志类似例如以下：
Mon Dec 22 10:03:04 CST 2014
RFS[1]: Archived Log: '+DATA/lixora/archivelog/1_23094_790186477.dbf'
Mon Dec 22 10:03:25 CST 2014
Media Recovery Log +DATA/lixora/archivelog/1_23094_790186477.dbf
Media Recovery Waiting for thread 1 sequence 23095 (in transit)
Mon Dec 22 10:05:53 CST 2014
RFS[2]: Archived Log: '+DATA/lixora/archivelog/1_23095_790186477.dbf'
Primary database is in MAXIMUM PERFORMANCE mode
RFS[2]: No standby redo logfiles of size 1024000 blocks exist
Mon Dec 22 10:05:55 CST 2014
Media Recovery Log +DATA/zhglptdg/archivelog/1_23095_790186477.dbf
Media Recovery Waiting for thread 1 sequence 23096 (in transit)
Mon Dec 22 10:05:57 CST 2014
RFS[2]: Archived Log: '+DATA/lixora/archivelog/1_23096_790186477.dbf'
Primary database is in MAXIMUM PERFORMANCE mode
RFS[2]: No standby redo logfiles of size 1024000 blocks exist
Mon Dec 22 10:06:00 CST 2014
Media Recovery Log +DATA/lixora/archivelog/1_23096_790186477.dbf
Media Recovery Waiting for thread 1 sequence 23097 (in transit)
类似一下日志，表明日志仅仅是传过来。可是没有应用：
Tue Dec 16 17:28:48 CST 2014
Primary database is in MAXIMUM PERFORMANCE mode
RFS[3]: Successfully opened standby log 7: '+DATA/lixora/onlinelog/group_7.360.857131345'
Tue Dec 16 18:57:12 CST 2014
Primary database is in MAXIMUM PERFORMANCE mode
RFS[3]: Successfully opened standby log 8: '+DATA/lixora/onlinelog/group_8.361.857131375'
Tue Dec 16 20:12:13 CST 2014
Primary database is in MAXIMUM PERFORMANCE mode
RFS[3]: Successfully opened standby log 7: '+DATA/lixora/onlinelog/group_7.360.857131345'
Tue Dec 16 21:40:39 CST 2014
Primary database is in MAXIMUM PERFORMANCE mode
RFS[3]: Successfully opened standby log 8: '+DATA/lixora/onlinelog/group_8.361.857131375'
怎样能够确保dg 正常：
1）v$archive_log.applied 是否为yes
2）主库切换日志：ALTER system swtich logfile。
看备库v$database.CURRENT_SCN 是否有增长？