一、模拟产生GAP
1.备库停止DG同步进程：
SQL> archive log list
Database log mode Archive Mode
Automatic archival Enabled
Archive destination /oracle/archive
Oldest online log sequence 72
Next log sequence to archive 0
Current log sequence 74
SQL> alter database recover managed standby database cancel;
Database altered.
SQL>
SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
2.主库切换多次归档：
SQL> archive log list
Database log mode Archive Mode
Automatic archival Enabled
Archive destination /oracle/archive
Oldest online log sequence 72
Next log sequence to archive 74
Current log sequence 74
SQL>
SQL>
SQL>
SQL> alter system switch logfile;
System altered.
SQL> /
System altered.
SQL> /
System altered.
SQL> /
System altered.
SQL> archive log list
Database log mode Archive Mode
Automatic archival Enabled
Archive destination /oracle/archive
Oldest online log sequence 76
Next log sequence to archive 78
Current log sequence 78
3.主库删除/移动最近几个归档日志：
[oracle@dgdb1 ~]$ cd /oracle/archive/
[oracle@dgdb1 archive]$ mv 1_74_1024761634.dbf 1_75_1024761634.dbf 1_76_1024761634.dbf 1_77_1024761634.dbf /home/oracle
4.备库开启同步进程：
SQL> alter database recover managed standby database using current logfile disconnect from session;
Database altered.
5.查看GAP：
SQL> select * from v$archive_gap;
THREAD# LOW_SEQUENCE# HIGH_SEQUENCE#
---------- ------------- --------------
1 73 77
SQL> SELECT max(sequence#) from v$archived_log where applied='YES';
MAX(SEQUENCE#)
--------------
73
丢失了74-77四个日志
二、恢复备库：
1.在主库上创建一个备库的控制文件：
SQL> alter database create standby controlfile as '/home/oracle/standby.ctl';
Database altered.
2.以备库的当前SCN号为起点，在主库上做一个增量备份
查询备库当前SCN：
SQL> select current_scn from v$database;
CURRENT_SCN
-----------
1248633
确认主备GAP期间是否新增数据文件：
SQL> select file# from v$datafile where creation_change# > =1248633;
如果存在新增数据文件，备库恢复时需要先restore新添加的数据文件。
主库根据备库scn号进行增量备份：
RMAN> run{
allocate channel c1 type disk;
allocate channel c2 type disk;
backup INCREMENTAL from scn 1248633 database format '/home/oracle/incre_%U';
release channel c1;
release channel c2;
}
2> 3> 4> 5> 6> 7>
allocated channel: c1
channel c1: SID=52 device type=DISK
allocated channel: c2
channel c2: SID=54 device type=DISK
Starting backup at 10-MAY-22
channel c1: starting full datafile backup set
channel c1: specifying datafile(s) in backup set
input datafile file number=00001 name=/u01/app/oracle/oradata/rmanpri/system01.dbf
input datafile file number=00004 name=/u01/app/oracle/oradata/rmanpri/users01.dbf
channel c1: starting piece 1 at 10-MAY-22
channel c2: starting full datafile backup set
channel c2: specifying datafile(s) in backup set
input datafile file number=00002 name=/u01/app/oracle/oradata/rmanpri/sysaux01.dbf
input datafile file number=00003 name=/u01/app/oracle/oradata/rmanpri/undotbs01.dbf
channel c2: starting piece 1 at 10-MAY-22
channel c2: finished piece 1 at 10-MAY-22
piece handle=/home/oracle/incre_0u0t5vb9_1_1 tag=TAG20220510T185433 comment=NONE
channel c2: backup set complete, elapsed time: 00:01:06
channel c2: starting full datafile backup set
channel c2: specifying datafile(s) in backup set
including current control file in backup set
channel c2: starting piece 1 at 10-MAY-22
channel c2: finished piece 1 at 10-MAY-22
piece handle=/home/oracle/incre_0v0t5vdb_1_1 tag=TAG20220510T185433 comment=NONE
channel c2: backup set complete, elapsed time: 00:00:01
channel c1: finished piece 1 at 10-MAY-22
piece handle=/home/oracle/incre_0t0t5vb9_1_1 tag=TAG20220510T185433 comment=NONE
channel c1: backup set complete, elapsed time: 00:01:10
Finished backup at 10-MAY-22
released channel: c1
released channel: c2
[oracle@dgdb1 trace]$ ll /home/oracle/
total 20404
-rw-r----- 1 oracle oinstall 221184 May 10 18:55 incre_0t0t5vb9_1_1
-rw-r----- 1 oracle oinstall 344064 May 10 18:55 incre_0u0t5vb9_1_1
-rw-r----- 1 oracle oinstall 10092544 May 10 18:55 incre_0v0t5vdb_1_1
-rw-r----- 1 oracle oinstall 10043392 May 10 18:48 standby.ctl
将增量备份和控制文件拷贝到备库上:
[oracle@dgdb1 trace]$ scp /home/oracle/incre_0* dgdb2:/home/oracle
oracle@dgdb2's password:
incre_0t0t5vb9_1_1 100% 216KB 216.0KB/s 00:00
incre_0u0t5vb9_1_1 100% 336KB 336.0KB/s 00:00
incre_0v0t5vdb_1_1 100% 9856KB 9.6MB/s 00:01
[oracle@dgdb1 trace]$ scp /home/oracle/standby.ctl dgdb2:/home/oracle
oracle@dgdb2's password:
standby.ctl
[oracle@dgdb2 trace]$ ll /home/oracle/
total 20216
-rw-r----- 1 oracle oinstall 221184 May 11 17:49 incre_0t0t5vb9_1_1
-rw-r----- 1 oracle oinstall 344064 May 11 17:49 incre_0u0t5vb9_1_1
-rw-r----- 1 oracle oinstall 10092544 May 11 17:49 incre_0v0t5vdb_1_1
-rw-r----- 1 oracle oinstall 10043392 May 11 17:50 standby.ctl
备库关闭数据库实例，开启至nomount状态：
SQL> alter database recover managed standby database cancel;
Database altered.
SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup nomount
ORACLE instance started.
Total System Global Area 584568832 bytes
Fixed Size 2255432 bytes
Variable Size 226493880 bytes
Database Buffers 352321536 bytes
Redo Buffers 3497984 bytes
备库恢复新的控制文件：
RMAN> restore controlfile from '/home/oracle/standby.ctl';
Starting restore at 11-MAY-22
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=19 device type=DISK
channel ORA_DISK_1: copied control file copy
output file name=/u01/app/oracle/oradata/rmanstd/control01.ctl
output file name=/u01/app/oracle/fast_recovery_area/rmanstd/control02.ctl
Finished restore at 11-MAY-22
备库开启到mount状态：
SQL> alter database mount;
Database altered.
确认取消日志应用:
SQL> alter database recover managed standby database cancel;
Database altered.
增量备份注册到RMAN的catalog：
RMAN> catalog start with '/home/oracle';
released channel: ORA_DISK_1
Starting implicit crosscheck backup at 11-MAY-22
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=19 device type=DISK
Crosschecked 9 objects
Finished implicit crosscheck backup at 11-MAY-22
Starting implicit crosscheck copy at 11-MAY-22
using channel ORA_DISK_1
Crosschecked 4 objects
Finished implicit crosscheck copy at 11-MAY-22
searching for all files in the recovery area
cataloging files...
no files cataloged
searching for all files that match the pattern /home/oracle
List of Files Unknown to the Database
=====================================
File Name: /home/oracle/.bashrc
File Name: /home/oracle/.bash_logout
File Name: /home/oracle/incre_0v0t5vdb_1_1
File Name: /home/oracle/.bash_history
File Name: /home/oracle/.oracle/logs/installActions2019-11-04_11-00-39AM.log
File Name: /home/oracle/.oracle/logs/oraInstall2019-11-04_11-00-39AM.out
File Name: /home/oracle/.oracle/logs/oraInstall2019-11-04_11-00-39AM.err
File Name: /home/oracle/.bash_profile
File Name: /home/oracle/incre_0u0t5vb9_1_1
File Name: /home/oracle/incre_0t0t5vb9_1_1
File Name: /home/oracle/.kshrc
File Name: /home/oracle/standby.ctl
File Name: /home/oracle/.viminfo
Do you really want to catalog the above files (enter YES or NO)? yes
cataloging files...
cataloging done
List of Cataloged Files
=======================
File Name: /home/oracle/incre_0v0t5vdb_1_1
File Name: /home/oracle/incre_0u0t5vb9_1_1
File Name: /home/oracle/incre_0t0t5vb9_1_1
File Name: /home/oracle/standby.ctl
备库开启恢复增量备份：
RMAN> recover database noredo;
Starting recover at 11-MAY-22
using channel ORA_DISK_1
channel ORA_DISK_1: starting incremental datafile backup set restore
channel ORA_DISK_1: specifying datafile(s) to restore from backup set
destination for restore of datafile 00001: /u01/app/oracle/oradata/rmanstd/system01.dbf
destination for restore of datafile 00004: /u01/app/oracle/oradata/rmanstd/users01.dbf
channel ORA_DISK_1: reading from backup piece /home/oracle/incre_0t0t5vb9_1_1
channel ORA_DISK_1: piece handle=/home/oracle/incre_0t0t5vb9_1_1 tag=TAG20220510T185433
channel ORA_DISK_1: restored backup piece 1
channel ORA_DISK_1: restore complete, elapsed time: 00:00:01
channel ORA_DISK_1: starting incremental datafile backup set restore
channel ORA_DISK_1: specifying datafile(s) to restore from backup set
destination for restore of datafile 00002: /u01/app/oracle/oradata/rmanstd/sysaux01.dbf
destination for restore of datafile 00003: /u01/app/oracle/oradata/rmanstd/undotbs01.dbf
channel ORA_DISK_1: reading from backup piece /home/oracle/incre_0u0t5vb9_1_1
channel ORA_DISK_1: piece handle=/home/oracle/incre_0u0t5vb9_1_1 tag=TAG20220510T185433
channel ORA_DISK_1: restored backup piece 1
channel ORA_DISK_1: restore complete, elapsed time: 00:00:01
Finished recover at 11-MAY-22
备库开启日志同步进程：
SQL> alter database recover managed standby database using current logfile disconnect from session;
Database altered.
查看GAP：
SQL> select * from v$archive_gap;
no rows selected
SQL> SELECT max(sequence#) from v$archived_log where applied='YES';
MAX(SEQUENCE#)
--------------
主库：
SQL> alter system switch logfile;
System altered.
SQL> archive log list
Database log mode Archive Mode
Automatic archival Enabled
Archive destination /oracle/archive
Oldest online log sequence 79
Next log sequence to archive 81
Current log sequence 81
备库：
SQL> archive log list
Database log mode Archive Mode
Automatic archival Enabled
Archive destination /oracle/archive
Oldest online log sequence 79
Next log sequence to archive 0
Current log sequence 81
GAP修复完成。
