第一部分 問題描述和環境狀態確認
----1. 問題場景
Oracle DataGuard主庫丟失archivelog，如何不重建備庫完成同步？
在Oracle DataGuard主從同步過程中可能出現主庫archivelog丟失，備庫出現gap錯誤。
此時，除了重新完整搭建DataGuard之外，可以通過主庫增量備份完成備份重新同步。
----2. 解決方式
【主要步驟】
1.在備庫上找出當前scn；
2.根據此scn，在主庫上使用rman完成增量備份；
3.傳輸增量備份到備庫，同時在備庫上恢復；
4.重新啟動備庫同步。
----3. 增量恢復詳細過程
==查看主庫信息==
SQL> select database_role from v$database;
DATABASE_ROLE
----------------
PRIMARY
SQL> archive log list;
==查看備庫信息==
SQL> select database_role from v$database;
DATABASE_ROLE
----------------
PHYSICAL STANDBY
--3.1.主、備庫上查看日志信息
SQL> select group#,thread#,sequence#,bytes,members,archived,status,first_change#,first_time from v$log;
---- #在主庫上 查看 LOG GAP 狀態
SQL>select dest_name,destination, database_mode, recovery_mode,gap_status from v$archive_dest_status where dest_id=2;
---- #在備庫上查詢
SELECT * FROM V$ARCHIVE_GAP;
====3.2 驗證主庫到備庫的歸檔日志傳輸情況和備庫上歸檔日志的APPLY情況
====3.2.1 在備庫上查看歸檔日志應用情況: val.applied='YES' --已應用; val.applied='NO' --待應用;
PhyStdby:SQL>select thread#, sequence#, val.applied
from v$archived_log val, v$database vdb
where val.resetlogs_change# = vdb.resetlogs_change#;
PhyStdby:SQL>select max(lh.SEQUENCE#) "Last applied arc",max(al.SEQUENCE#) "Last recieved arc"
from v$log_history lh,v$archived_log al;
------ 驗證最大日志序列號
Primary: SQL> select thread#, max(sequence#) "Last Primary Seq Generated"
from v$archived_log val, v$database vdb
where val.resetlogs_change# = vdb.resetlogs_change#
group by thread# order by 1;
PhyStdby:SQL> select thread#, max(sequence#) "Last Standby Seq Received"
from v$archived_log val, v$database vdb
where val.resetlogs_change# = vdb.resetlogs_change#
group by thread# order by 1;
------ "Last Standby Seq Applied"
PhyStdby:SQL>select thread#, max(sequence#) "Last Standby Seq Applied"
from v$archived_log val, v$database vdb
where val.resetlogs_change# = vdb.resetlogs_change#
and val.applied='YES'
group by thread# order by 1;
----================================================================
====第二部分 利用rman進行增量scn的恢復
==利用rman進行增量scn的恢復==
1.在備庫上取消日志應用
SQL> alter database recover managed standby database cancel;
2.查看備庫scn
SQL> select current_scn from v$database;
---- select to_char(current_scn) from v$database;
CURRENT_SCN
---------------
13402877625847
3.根據scn，在主庫上進行rman增量備份
Primary: rman> rman target /
RMAN> backup incremental from scn 13402877625847 database format 'E:\ForStandby_%U.bka' tag 'forstandby';
------backup as compressed backupset incremental from scn 13402877625847 database format 'E:\ForStandby_%U.bka' tag 'forstandby';
RMAN> backup current controlfile for standby format 'E:\ForStandbyCTRL.bkc';
4.查看增量備份信息
E:\temp> dir
5.copy增量備份到備庫主機 一目錄，如: E:\temp
6.將備庫啟動到mount狀態
SQL> select open_mode from v$database;
OPEN_MODE
--------------------
READ ONLY
SQL> shutdown immediate;
SQL> startup nomount;
SQL> alter database mount standby database;
SQL> exit
7.rman恢復增量備份和控制文件備份
rman target / nocatalog
RMAN> crosscheck archivelog all;
RMAN> delete expired archivelog all;
RMAN> DELETE NOPROMPT ARCHIVELOG ALL COMPLETED BEFORE 'SYSDATE-15';
RMAN> catalog start with 'E:\temp'; ####注冊增量備份文件
Do you really want to catalog the above files (enter YES or NO)? yes
RMAN> RECOVER DATABASE NOREDO; #### 注意 NOREDO 選項
SQL> shutdown;
SQL> startup nomount;
RMAN> restore standby controlfile from 'E:\temp\ForStandbyCTRL.bkc';
RMAN> shutdown;
RMAN> exit
8.啟動備庫到mount狀態
SQL> startup nomount;
SQL> alter database mount standby database;
9.由於恢復了控制文件，因此需要重新添加新的standby redo log file(若先前有，可忽略此步)
alter database add standby logfile group 11 ('D:\APP\ADMINISTRATOR\WHBIDB_REDO\STANDBY11.LOG') size 1024m;
alter database add standby logfile group 12 ('D:\APP\ADMINISTRATOR\WHBIDB_REDO\STANDBY12.LOG') size 1024m;
alter database add standby logfile group 13 ('D:\APP\ADMINISTRATOR\WHBIDB_REDO\STANDBY13.LOG') size 1024m;
alter database add standby logfile group 14 ('D:\APP\ADMINISTRATOR\WHBIDB_REDO\STANDBY14.LOG') size 1024m;
alter database add standby logfile group 15 ('D:\APP\ADMINISTRATOR\WHBIDB_REDO\STANDBY15.LOG') size 1024m;
alter database add standby logfile group 16 ('D:\APP\ADMINISTRATOR\WHBIDB_REDO\STANDBY16.LOG') size 1024m;
10.啟動備庫同步
SQL> alter database open read only;
Database altered.
SQL> alter database recover managed standby database disconnect from session using current logfile;
Database altered.
11.查看歸檔日志應用以及表數據是否恢復
SQL> select max(lh.SEQUENCE#) "Lastapplied arc", max(al.SEQUENCE#) "Last recieved arc"
from v$log_history lh,v$archived_log al;
SQL> select count(1) from dba_tables;
----在備庫上查看歸檔日志應用情況: val.applied='YES' --已應用; val.applied='NO' --待應用;
PhyStdby:SQL>select thread#, sequence#, val.applied
from v$archived_log val, v$database vdb
where val.resetlogs_change# = vdb.resetlogs_change#;