1.清空归档日志
RMAN> crosscheck archivelog all;
RMAN> delete achivelog all;
2.清空数据文件。
select name from v$datafile;
rm v$datafile
3.恢复数据
Solution
How to restore a complete database from an RMAN backup
This note assumes an RMAN catalog is not available. The use of a
catalog is optional in this scenario as the backup information is
available in the controlfile.
Prior to restoring a database you must ensure you have a valid RMAN backup.
In this example we will assume all files are required to be restored:
* Datafiles
* Controlfiles
* Archivelogs (In order to perform recovery)
Online redo logs and temp files are recreated automatically by RMAN
when a resetlogs is issued. Online redo logs and temp files are not
backed up by RMAN
Step 1: Identify controlfile backup to restore
Note: If you do not need to restore a controlfile proceed to step 3.
* Locate the RMAN backup you wish to restore.
* These files should be located in the directory where they were backed up to.
* If you have the RMAN backup log available this will also be of assistance.
Within the RMAN backup log you will see the controlfile is backed up last the the piece handle is shown.
....
including current control file in backup set
including current SPFILE in backup set
channel ORA_DISK_1: starting piece 1 at 2009/01/01 12:00:00
channel ORA_DISK_1: finished piece 1 at 2009/01/01 12:00:02
piece handle=/recovery_area/V11/backupset/2009_05_0 /o1_mf_ncsnf_TAG20090506T11_501tr0h7_.bkp tag=TAG20090506T11 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:02
If you do not have an RMAN backup log simply locate the last file RMAN backed up. This should contain the controlfile backup.
Step 2: Restore the controlfile
2a) If you DO NOT have a spfile.
If you do have an spfile or init.ora move to Step 2b
If you do not have a valid spfile or init.ora
RMAN has the ability to nomount an instance without the requirement of a
spfile. This will allow you to restore your spfile from a valid backup.
% rman target /
RMAN> startup nomount force;
You will see this message:
..
starting Oracle instance without parameter file for retrieval of spfile
..
At this point you can restore the spfile:
RMAN> restore spfile from ‘/recovery_area/V11/backupset/2009_05_05/o1_mf_ncsnf_TAG20_501tr0h7_.bkp‘;
RMAN> shutdown immediate;
Once the spfile has been successfully restored proceed to Step 2b.
2b)
SQL> startup nomount;
Following the successful nomount of the instance you are ready to restore the
controlfile;
NOTE: The controlfile will be restored to the following location:
SQL> show parameter control_files
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
control_files string /oradata/V11/control01.ctl
% rman target /
You will see the message:
connected to target database: V11 (not mounted)
RMAN> restore controlfile from ‘/recovery_area/V11/backupset/2009_05_06/o1_mf_ncsnf_TAG20090506T113947_501tr0h7_.bkp‘;
Starting restore at 2009/05/11 11:01:26
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=151 device type=DISK
channel ORA_DISK_1: restoring control file
channel ORA_DISK_1: restore complete, elapsed time: 00:00:01
output file name=/oradata/V11/control01.ctl
Finished restore at 2009/05/11 11:01:27
In this example the controlfile has been restored to ‘/oradata/V11/control01.ctl‘
Step 3: Restore and recover the database
Your next task is to restore the database and perform recovery. Mount the database now that the controlfile has been restored:
RMAN> alter database mount;
Now you have two options for recovery.
1) Full/Complete recovery.
2) Point In Time Recovery (PIT)
In both examples it is assumed that all archivelogs are available to perform the recovery.
Full recovery
==========
To Perform a full restore and recovery.
run{
restore database;
recover database;
alter database open resetlogs;
}
If you performed a complete recovery with current controlfile
and online redologs in place, you might get below error when opening the
database with resetlogs:
ORA-01139: RESET LOGS option only valid after an incomplete database recovery
At this point simply open the database without resetlogs option.
PITR Recovery
===========
Point-In-Time Recovery (PITR) would be used if you have decided to
restore a database to a particular point in time. This may be warranted
for a hardware fault or if you are aware of a database corruption that
occured at a certain date/time.
run{
set until time "to_date(‘Aug 16 2014 10:30:00‘,‘Mon DD YYYY HH24:MI:SS‘)";
restore database;
recover database;
sql ‘alter database open resetlogs‘;
}
NOTE: The above scripts may be altered to allocate more
channels. Good practice would be to review the backup log and use the
same number of channels for restore as that used by the backup.