1. 首先來模拟Gap的産生
1.1. 備庫關閉：
[email protected]_s>shutdown immediate;
1.2. 主庫切換日志
[email protected]>select SEQUENCE#,ARCHIVED,STATUS from v$log;
SEQUENCE# ARC STATUS
---------- --- ----------------
61 YES ACTIVE
62 YES ACTIVE
63 NO CURRENT
[email protected]>alter system archive log current;
System altered.
[email protected]>select SEQUENCE#,ARCHIVED,STATUS from v$log;
SEQUENCE# ARC STATUS
---------- --- ----------------
64 NO CURRENT
62 YES ACTIVE
63 YES ACTIVE
剛才current的日志已經歸檔
1.3. 删除歸檔，産生UNRESOLVABLE GAP
現在删除63号歸檔
[[email protected] arch]$ mv 1_63_909786801.dbf 1_63_909786801.dbf.bak
2. 檢視報錯
2.1. 啟動備庫
[email protected]_s>startup
2.2. 檢視備庫的alert
Media Recovery Log /u01/app/oracle/arch/1_62_909786801.dbf
Media Recovery Waiting for thread 1 sequence 63
Fetching gap sequence in thread 1, gap sequence 63-63
Fri May 06 05:28:09 2016
FAL[client]: Failed to request gap sequence
GAP - thread 1 sequence 63-63
DBID 3866310445 branch 909786801
FAL[client]: All defined FAL servers have been attempted.
------------------------------------------------------------
Check that the CONTROL_FILE_RECORD_KEEP_TIME initialization
parameter is defined to a value that's sufficiently large
enough to maintain adequate log switch information to resolve
archivelog gaps.
------------------------------------------------------------
2.3. 主庫查詢SWITCHOVER_STATUS
[email protected]>SELECT SWITCHOVER_STATUS FROM V$DATABASE;
SWITCHOVER_STATUS
--------------------
UNRESOLVABLE GAP
為UNRESOLVABLE GAP，說明此時的GAP需要我們自己手工去修複，無法自動修複，可自動修複的GAP顯示為RESOLVABLE GAP
3. 基于SCM的增量備份修複GAP
3.1. 在備庫上查詢current scn号
[email protected]_s>select current_scn from v$database;
CURRENT_SCN
-----------
2567388
3.2. 到主庫去進行基于此SCN的增量備份
RMAN> BACKUP INCREMENTAL FROM SCN 2567388 DATABASE FORMAT '/u01/app/oracle/oradata/tmp/ora11_scn_%U' tag 'For Standby Gap';
3.3. 傳輸到備庫：
[[email protected] tmp]$ scp * standby:/u01/app/oracle/oradata/tmp
[email protected]'s password:
ora11_scn_0kr54hvk_1_1 100% 125MB 125.2MB/s 00:01
ora11_scn_0lr54l99_1_1 100% 9664KB 9.4MB/s 00:00
3.4. 備庫重新啟動到mount，并取消日志應用
[email protected]_s>shutdown immediate;
[email protected]_s>startup mount;
[email protected]_s>alter database recover managed standby database cancel;
3.5. 注冊剛才傳輸過來的備份集
RMAN> CATALOG START WITH '/u01/app/oracle/oradata/tmp';
3.6. recover備庫
RMAN> recover database noredo;
恢複完畢，這時我們可以觀察備庫的alert日志：
Incremental restore complete of datafile 4 /u01/app/oracle/oradata/dgtest_s/users01.dbf
checkpoint is 2893208
last deallocation scn is 3
Incremental restore complete of datafile 3 /u01/app/oracle/oradata/dgtest_s/undotbs01.dbf
checkpoint is 2893208
last deallocation scn is 973300
Incremental restore complete of datafile 5 /u01/app/oracle/oradata/dgtest_s/example01.dbf
checkpoint is 2893208
last deallocation scn is 942056
Mon May 09 05:20:25 2016
Incremental restore complete of datafile 2 /u01/app/oracle/oradata/dgtest_s/sysaux01.dbf
checkpoint is 2893208
last deallocation scn is 956093
Incremental restore complete of datafile 1 /u01/app/oracle/oradata/dgtest_s/system01.dbf
checkpoint is 2893208
last deallocation scn is 955346
發現資料檔案的scn号都已經重新重新整理，但是此時還不能重新起庫，需要重新從主庫生成一個standby controlfile。
3.7. 主庫備份控制檔案
RMAN> BACKUP CURRENT CONTROLFILE FOR STANDBY FORMAT '/u01/app/oracle/oradata/tmp/ctl.bak';
3.8. 傳輸standby控制檔案到備庫
[email protected]'s password:
ctl.bak 100% 9664KB 9.4MB/s 00:00
3.9. 備庫恢複standby控制檔案
備庫庫起到nomount階段：
[email protected]_s>shutdown immediate
[email protected]_s>startup nomount;
rman恢複控制檔案
RMAN> RESTORE STANDBY CONTROLFILE FROM '/u01/app/oracle/oradata/tmp/ctl.bak';
3.10. mount備庫，并取消日志應用
[email protected]_s> alter database mount;
[email protected]_s>alter database recover managed standby database cancel;
3.11. 清空備庫日志組
[email protected]_s>ALTER DATABASE CLEAR LOGFILE GROUP 1;
Database altered.
注：如果采用了standby log模式，不需要清空，如果清空會出現
SQL> ALTER DATABASE CLEAR LOGFILE GROUP 1;
ALTER DATABASE CLEAR LOGFILE GROUP 1
*
ERROR at line 1:
ORA-19527: physical standby redo log must be renamed
ORA-00312: online log 1 thread 1: '/u01/oradata/badly9/redo01.log'
說明：如果沒有采用standby log模式，有幾組需要清空幾組
3.12. 備庫重設flashback
[email protected]_s>ALTER DATABASE FLASHBACK OFF;
[email protected]_s>ALTER DATABASE FLASHBACK ON;
3.13. 備庫開始應用日志
[email protected]_s>ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT LOGFILE DISCONNECT FROM SESSION;
4. 确認修複成功
在主庫中執行
[email protected]>alter system switch logfile;
分别主備庫中執行select max(sequence#) from v$archived_log;如果一緻标示修複成功
[email protected]>select max(sequence#) from v$archived_log;
MAX(SEQUENCE#)
--------------
81
[email protected]_s>select max(sequence#) from v$archived_log;
MAX(SEQUENCE#)
--------------
81
至此GAP修複完畢。
![【Oracle】OPatch更新[圖]](data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACwAAAAAAQABAAACAkQBADs=)