Oracle RMAN Recover中使用BBED跳过缺失的归档继续Recover的测试
一.背景说明
Oracle RMAN 备份的恢复分2个步骤：RESTRE 和 RECOVER。
在这个过程中，Recover 是依赖与归档文件的。
假设一种情况：周一对数据库做了全备，然后保留归档。周四发现数据库有异常，准备恢复，发现周二的时候少了一个归档。
按照正常的情况，我们只能将数据库恢复到周二缺失归档的之前的点。
那么我这里就是一个研究，如何跳过这个缺失的归档，让数据库继续进行Recover。
根据测试结果，Recover 是可以继续，但是测试的结果意义不是很大，因为还是有数据丢失。
所以这里更多的是对这种方法的抛砖引玉。
二.测试案例
2.1 使用RMAN 全备数据库
此步骤直接备份即可。
2.2 创建测试表dave1并切换归档
SQL> select sequence# from v$log wherethread#=1;
SEQUENCE#
----------
152
151
SQL> create table dave1 as select * fromdba_users;
Table created.
SQL> alter system switch logfile;
System altered.
SQL> select sequence# from v$log wherethread#=1;
SEQUENCE#
----------
152
153
2.3 创建测试表dave2并切换归档
SQL> create table dave2 as select * fromdba_users;
Table created.
SQL> alter system switch logfile;
System altered.
SQL> select sequence#,status from v$logwhere thread#=1;
SEQUENCE# STATUS
---------- ----------------
154 CURRENT
153 ACTIVE
SQL> select sequence# fromv$archived_log where thread#=1;
SEQUENCE#
----------
148
149
150
151
152
153
6 rows selected.
2.4 删除153的归档
[oracle@dave arch]$ ll
total 42200
-rw-r-----. 1 oracle oinstall 42715136Jul 5 22:56 1_125_816661296.dbf
-rw-r-----. 1 oracle oinstall 248320 Jul 6 23:14 1_152_816661296.dbf
-rw-r-----. 1 oracle oinstall 127488 Jul 6 23:15 1_153_816661296.dbf
-rw-r-----. 1 oracle oinstall 113664 Jul 6 23:19 1_154_816661296.dbf
[oracle@dave arch]$ rm-rf 1_153_816661296.dbf
[oracle@dave arch]$ ll
total 42072
-rw-r-----. 1 oracle oinstall 42715136Jul 5 22:56 1_125_816661296.dbf
-rw-r-----. 1 oracle oinstall 248320 Jul 6 23:14 1_152_816661296.dbf
-rw-r-----. 1 oracle oinstall 113664 Jul 6 23:19 1_154_816661296.dbf
[oracle@dave arch]$
2.5 然后进行restore 和recover
SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL>
SQL> startup mount
RMAN> restore database;
Starting restore at 06-JUL-13
released channel: ORA_DISK_1
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=20 device type=DISK
channel ORA_DISK_1: starting datafilebackup set restore
channel ORA_DISK_1: specifying datafile(s)to restore from backup set
channel ORA_DISK_1: restoring datafile00001 to /u01/app/oracle/oradata/dave/system.256.816661027
channel ORA_DISK_1: restoring datafile00003 to /u01/app/oracle/oradata/dave/undotbs1.258.816661037
channel ORA_DISK_1: restoring datafile00005 to /u01/app/oracle/oradata/dave/undotbs2.265.816661787
channel ORA_DISK_1: reading from backuppiece /u01/backup/dave_lev0_06oe3kdv_1_1_20130706
channel ORA_DISK_1: piecehandle=/u01/backup/dave_lev0_06oe3kdv_1_1_20130706 tag=DAVE_LEV0
channel ORA_DISK_1: restored backup piece 1
channel ORA_DISK_1: restore complete,elapsed time: 00:00:25
channel ORA_DISK_1: starting datafilebackup set restore
channel ORA_DISK_1: specifying datafile(s)to restore from backup set
channel ORA_DISK_1: restoring datafile00002 to /u01/app/oracle/oradata/dave/sysaux.257.816661033
channel ORA_DISK_1: restoring datafile00004 to /u01/app/oracle/oradata/dave/users.259.816661039
channel ORA_DISK_1: restoring datafile00006 to /u01/app/oracle/oradata/dave/dave01.dbf
channel ORA_DISK_1: restoring datafile00007 to /u01/app/oracle/oradata/dave/dave02.dbf
channel ORA_DISK_1: reading from backuppiece /u01/backup/dave_lev0_05oe3kdv_1_1_20130706
channel ORA_DISK_1: piece handle=/u01/backup/dave_lev0_05oe3kdv_1_1_20130706tag=DAVE_LEV0
channel ORA_DISK_1: restored backup piece 1
channel ORA_DISK_1: restore complete,elapsed time: 00:00:25
Finished restore at 06-JUL-13
RMAN>
RMAN> recoverdatabase;
Starting recover at 06-JUL-13
using channel ORA_DISK_1
starting media recovery
archived log for thread 1 with sequence 152is already on disk as file /u01/arch/1_152_816661296.dbf
archived log for thread 1 with sequence 154is already on disk as file /u01/arch/1_154_816661296.dbf
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGESTACK FOLLOWS ===============
RMAN-00571:===========================================================
RMAN-03002: failure of recover command at07/06/2013 23:23:48
RMAN-06053: unable to perform mediarecovery because of missing log
RMAN-06025: no backup ofarchived log for thread 1 with sequence 153 and starting SCN of 3836001 foundto restore
RMAN>
这个153 是我们刚才手工删掉的归档。如果这个不搞定，后面没办法恢复。
2.6 BBED 推荐SCN
2.6.1 修改原理说明
-- System Checkpoint SCN：
SQL> select checkpoint_change# fromv$database;
CHECKPOINT_CHANGE#
------------------
3836654
--- Datafile CheckpointSCN：
SQL> select name,checkpoint_change# fromv$datafile;
NAME CHECKPOINT_CHANGE#
-------------------------------------------------------------------------
/u01/app/oracle/oradata/dave/system.256.816661027 3836654
/u01/app/oracle/oradata/dave/sysaux.257.816661033 3836654
/u01/app/oracle/oradata/dave/undotbs1.258.816661037 &n
