ALTER DATABASE BEGIN BACKUP and ALTER DATABASE END BACKUP

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>