I logged into an Oracle 12.1 database, checked it was in ARCHIVELOG mode then ran the ALTER DATABASE BEGIN BACKUP command. This told Oracle I was about to do a hot backup:
C:\Users\Andrew>sqlplus / as sysdba
SQL*Plus: Release 12.1.0.1.0 Production on Wed Mar 18 14:45:56 2015
Copyright (c) 1982, 2013, Oracle. All rights reserved.
Connected to:
Oracle Database 12c Enterprise Edition Release 12.1.0.1.0 - 64bit Production
With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options
SQL> select log_mode from v$database
2 /
LOG_MODE
------------
ARCHIVELOG
SQL> alter database begin backup
2 /
Database altered.
SQL>
I
copied the database’s datafiles to somewhere safe. I didn’t bother about
the control files or the redo log files as I didn’t intend to do
anything to them in this example. Clearly, if you try this yourself, you
need to work out where the datafiles are beforehand:
C:\app\Administrator\oradata\ORCL1\DATAFILE>copy * Z:\Data\Oracle_Backup
O1_MF_SYSAUX_BDGVW9OT_.DBF
O1_MF_SYSTEM_BDGVZ93W_.DBF
O1_MF_TEMP_BDGW88KG_.TMP
O1_MF_UNDOTBS1_BDGW2MY6_.DBF
O1_MF_USERS_BDGW2LNZ_.DBF
5 file(s) copied.
C:\app\Administrator\oradata\ORCL1\DATAFILE>
I created a MARKER table to prove that the backup and restore had worked as planned:
SQL> create table marker as
2 select 'Andrew was here' message
3 from dual
4 /
Table created.
SQL>
Then I used the ALTER DATABASE END BACKUP command to tell Oracle the hot backup was finished and closed the database:
SQL> alter database end backup;
Database altered.
SQL> shutdown
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL>
I deleted the database’s datafiles:
C:\app\Administrator\oradata\ORCL1\DATAFILE>dir
Volume in drive C has no label.
Volume Serial Number is 269C-9AD9
Directory of C:\app\Administrator\oradata\ORCL1\DATAFILE
27/01/2015 11:05 <DIR> .
27/01/2015 11:05 <DIR> ..
18/03/2015 15:09 3,722,452,992 O1_MF_SYSAUX_BDGVW9OT_.DBF
18/03/2015 15:09 964,698,112 O1_MF_SYSTEM_BDGVZ93W_.DBF
18/03/2015 14:27 1,906,319,360 O1_MF_TEMP_BDGW88KG_.TMP
18/03/2015 15:09 1,378,885,632 O1_MF_UNDOTBS1_BDGW2MY6_.DBF
18/03/2015 15:09 4,650,442,752 O1_MF_USERS_BDGW2LNZ_.DBF
5 File(s) 12,622,798,848 bytes
2 Dir(s) 6,003,765,248 bytes free
C:\app\Administrator\oradata\ORCL1\DATAFILE>del *.*
C:\app\Administrator\oradata\ORCL1\DATAFILE\*.*, Are you sure (Y/N)? y
C:\app\Administrator\oradata\ORCL1\DATAFILE>
Then
I restored them from the backup which I made earlier. Again, if you are
doing this yourself, you need to work out which files have been lost
before you can restore them:
Z:\Data\Oracle_Backup>copy *.* C:\app\Administrator\oradata\ORCL1\DATAFILE
O1_MF_SYSAUX_BDGVW9OT_.DBF
O1_MF_SYSTEM_BDGVZ93W_.DBF
O1_MF_TEMP_BDGW88KG_.TMP
O1_MF_UNDOTBS1_BDGW2MY6_.DBF
O1_MF_USERS_BDGW2LNZ_.DBF
5 file(s) copied.
Z:\Data\Oracle_Backup>
Finally, I mounted the database, recovered it, opened it and confirmed that the MARKER table was still there:
Z:\Data\Oracle_Backup>sqlplus / as sysdba
SQL*Plus: Release 12.1.0.1.0 Production on Wed Mar 18 15:50:55 2015
Copyright (c) 1982, 2013, Oracle. All rights reserved.
Connected to an idle instance.
SQL> startup mount
ORACLE instance started.
Total System Global Area 1720328192 bytes
Fixed Size 2403496 bytes
Variable Size 1023411032 bytes
Database Buffers 687865856 bytes
Redo Buffers 6647808 bytes
Database mounted.
SQL> recover database
Media recovery complete.
SQL> alter database open
2 /
Database altered.
SQL> select * from marker
2 /
MESSAGE
---------------
Andrew was here
SQL>
