Dataguard环境下的备份与恢复

 在部署完active data guard后，不但可以将只读的查询交给备库执行，还可以把日常的数据库备份工作放在备库上执行，从而减轻主库的压力，充分的发挥服务器资源，下面演示下利用备库备份来还原主库数据的过程！

一：主库上创建表空间，并在表空间上建表，插入测试数据，同时检查备库的同步情况

SQL> create tablespace test01 datafile '/u01/app/oracle/oradata/db1/test01.dbf' size 10M;Tablespace created.
SQL> create table rman tablespace test01 as select object_id,object_name from dba_objects;
Table created.

SQL> select count(*) from rman;

  COUNT(*)
----------
     76379

[oracle@db2 db1]$ sqlplus  /nolog
SQL*Plus: Release 11.2.0.3.0 Production on Mon Oct 29 11:37:38 2012
Copyright (c) 1982, 2011, Oracle.  All rights reserved.

SQL> conn /as sysdba
Connected.
SQL> select count(*) from rman;

  COUNT(*)
----------
     76379

二：在备库上使用rman对新建的表空间test01进行备份

[oracle@db2 db1]$ rman target /
Recovery Manager: Release 11.2.0.3.0 - Production on Mon Oct 29 11:38:01 2012
Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.
connected to target database: DB1 (DBID=1387827106)

RMAN> report schema;

RMAN> backup tablespace test01 format '/home/oracle/test01_%U';

Starting backup at 2012-10-29-11:38:50
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=1 device type=DISK
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
input datafile file number=00034 name=/u01/app/oracle/oradata/db1/test01.dbf
channel ORA_DISK_1: starting piece 1 at 2012-10-29-11:38:51
channel ORA_DISK_1: finished piece 1 at 2012-10-29-11:38:52
piece handle=/home/oracle/test01_03novc2b_1_1 tag=TAG20121029T113851 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
Finished backup at 2012-10-29-11:38:52

三：关闭主库后删除表空间数据文件，模拟数据丢失场景

[oracle@db1 ~]$ sqlplus /nolog
SQL*Plus: Release 11.2.0.3.0 Production on Mon Oct 29 11:39:49 2012
Copyright (c) 1982, 2011, Oracle.  All rights reserved.

SQL> conn /as sysdba
Connected.
SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> exit

[oracle@db1 ~]$ rm -rf /u01/app/oracle/oradata/db1/test01.dbf

四：重新启动主库，只能启动到mount状态

[oracle@db1 ~]$ sqlplus  /nolog
SQL*Plus: Release 11.2.0.3.0 Production on Mon Oct 29 11:41:42 2012
Copyright (c) 1982, 2011, Oracle.  All rights reserved.
SQL> conn /as sysdba
Connected to an idle instance.
SQL> startup
ORACLE instance started.

Total System Global Area 1536602112 bytes
Fixed Size                  2228624 bytes
Variable Size            1174408816 bytes
Database Buffers          352321536 bytes
Redo Buffers                7643136 bytes
Database mounted.
ORA-01157: cannot identify/lock data file 34 - see DBWR trace file
ORA-01110: data file 34: '/u01/app/oracle/oradata/db1/test01.dbf'

SQL> select open_mode,database_role from v$database;

OPEN_MODE            DATABASE_ROLE
-------------------- ----------------
MOUNTED              PRIMARY

五:将备库的备份数据复制到主库，并使用catalog命令注册到主库的控制文件中

[oracle@db2 ~]$ scp test01_03novc2b_1_1 db1:/home/oracle/
[oracle@db1 ~]$ rman target /
Recovery Manager: Release 11.2.0.3.0 - Production on Mon Oct 29 11:45:02 2012
Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.
connected to target database: DB1 (DBID=1387827106, not open)

RMAN> list backup of tablespace test01;
specification does not match any backup in the repository

RMAN>  catalog backuppiece '/home/oracle/test01_03novc2b_1_1';

cataloged backup piece
backup piece handle=/home/oracle/test01_03novc2b_1_1 RECID=42 STAMP=797946436

RMAN> list backup of tablespace test01;

List of Backup Sets
===================

BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ -------------------
42      Full    3.98M      DISK        00:00:00     2012-10-29-11:38:51
        BP Key: 42   Status: AVAILABLE  Compressed: NO  Tag: TAG20121029T113851
        Piece Name: /home/oracle/test01_03novc2b_1_1
  List of Datafiles in backup set 42
  File LV Type Ckp SCN    Ckp Time            Name
  ---- -- ---- ---------- ------------------- ----
  34      Full 10350465   2012-10-29-11:35:32 /u01/app/oracle/oradata/db1/test01.dbf

六：还原和恢复表空间test01，并将主库启动到读写状态，测试主备库数据实时同步情况

RMAN> restore tablespace test01;
Starting restore at 2012-10-29-11:47:50
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=21 device type=DISK

channel ORA_DISK_1: starting datafile backup set restore
channel ORA_DISK_1: specifying datafile(s) to restore from backup set
channel ORA_DISK_1: restoring datafile 00034 to /u01/app/oracle/oradata/db1/test01.dbf
channel ORA_DISK_1: reading from backup piece /home/oracle/test01_03novc2b_1_1
channel ORA_DISK_1: piece handle=/home/oracle/test01_03novc2b_1_1 tag=TAG20121029T113851
channel ORA_DISK_1: restored backup piece 1
channel ORA_DISK_1: restore complete, elapsed time: 00:00:01
Finished restore at 2012-10-29-11:47:52

RMAN> recover tablespace test01;
Starting recover at 2012-10-29-11:48:02
using channel ORA_DISK_1

starting media recovery
media recovery complete, elapsed time: 00:00:01

Finished recover at 2012-10-29-11:48:03

RMAN> alter database open;
database opened

[oracle@db1 ~]$ sqlplus  /nolog
SQL*Plus: Release 11.2.0.3.0 Production on Mon Oct 29 11:48:47 2012
Copyright (c) 1982, 2011, Oracle.  All rights reserved.

SQL> conn /as sysdba
Connected.
SQL> truncate table rman;
Table truncated.

[oracle@db2 ~]$ sqlplus  /nolog
SQL*Plus: Release 11.2.0.3.0 Production on Mon Oct 29 11:49:12 2012
Copyright (c) 1982, 2011, Oracle.  All rights reserved.

SQL> conn /as sysdba
Connected.
SQL> select count(*) from rman;

  COUNT(*)
----------
         0