Recovery of a dropped tablespace

Recovery of a dropped tablespace

To recover from a case of a dropped tablespace, the Tablespace Point In Time Recovery (TSPITR) method cannot be used.

When you drop a tablespace, the controlfile will then no longer have any records of the tablespace which has been dropped. Attempts to use the RMAN RECOVER TABLESPACE command will return the RMAN error RMAN-06019 – “could not translate tablespace name” as shown below.

SQL> drop tablespace rman10 including contents and datafiles;

Tablespace dropped.

testdb:/u01/oracle/diag/rdbms/apex/apex/trace> rman target /

Recovery Manager: Release 10.2.0.4.0 - Production on Mon Jan 10 11:53:58 2009

Copyright (c) 1982, 2007, Oracle.  All rights reserved.

connected to target database: TESTDB (DBID=2469552796)

RMAN> restore tablespace rman10;

Starting restore at 10-JAN-18

using target database control file instead of recovery catalog

allocated channel: ORA_SBT_TAPE_1

channel ORA_SBT_TAPE_1: sid=141 devtype=SBT_TAPE

channel ORA_SBT_TAPE_1: Data Protection for Oracle: version 5.5.1.0

allocated channel: ORA_DISK_1

channel ORA_DISK_1: sid=140 devtype=DISK

RMAN-00571: ===========================================================

RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============

RMAN-00571: ===========================================================

RMAN-03002: failure of restore command at 10/01/2018 11:54:11

RMAN-20202: tablespace not found in the recovery catalog

So to recover from a dropped tablespace, we have two options:

1)  Do a point in time recovery of the whole database until the time the tablespace was dropped.

2)  Create a clone of the database from a valid backup, export the required tables from the tablespace which has been dropped, recreate the tablespace and then import the tables from the clone.

The first option will require an outage of the entire database and the entire database will be rolled back in tine in order to recover the tablespace.

Let us examine the first option using the example shown below:

In this example, CONTROLFILE AUTOBACKUP has been turned on and Flashback has been enabled for the database.

With Flashback enabled, the db_recovery_file_dest will have a sub-directory ‘autobackup’ as shown below for each day

We will Take full Backup.

backup database plus archivelog;

Starting backup at 10-JAN-18
current log archived
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=28 device type=DISK
channel ORA_DISK_1: starting archived log backup set
channel ORA_DISK_1: specifying archived log(s) in backup set
input archived log thread=1 sequence=1 RECID=24 STAMP=965056892
channel ORA_DISK_1: starting piece 1 at 10-JAN-18
channel ORA_DISK_1: finished piece 1 at 10-JAN-18
piece handle=/u01/app/oracle/fast_recovery_area/ORCL/backupset/2018_01_10/o1_mf_annnn_TAG20180110T152133_f5crk5bz_.bkp tag=TAG20180110T152133 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
channel ORA_DISK_1: starting archived log backup set
channel ORA_DISK_1: specifying archived log(s) in backup set
input archived log thread=1 sequence=13 RECID=15 STAMP=965046171
input archived log thread=1 sequence=14 RECID=22 STAMP=965047189
input archived log thread=1 sequence=15 RECID=23 STAMP=965047189
input archived log thread=1 sequence=16 RECID=21 STAMP=965047189
channel ORA_DISK_1: starting piece 1 at 10-JAN-18
channel ORA_DISK_1: finished piece 1 at 10-JAN-18
piece handle=/u01/app/oracle/fast_recovery_area/ORCL/backupset/2018_01_10/o1_mf_annnn_TAG20180110T152133_f5crk6g0_.bkp tag=TAG20180110T152133 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
Finished backup at 10-JAN-18

Starting backup at 10-JAN-18
using channel ORA_DISK_1
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
input datafile file number=00005 name=/u01/app/oracle/oradata/orcl/example01.dbf
input datafile file number=00001 name=/u01/app/oracle/oradata/orcl/system01.dbf
input datafile file number=00003 name=/u01/app/oracle/oradata/orcl/sysaux01.dbf
input datafile file number=00002 name=/u01/app/oracle/oradata/orcl/drtbs1.dbf
input datafile file number=00007 name=/u01/app/oracle/oradata/orcl/drtbs2.
dbf
input datafile file number=00008 name=/u01/app/oracle/oradata/orcl/arul1.dbf
input datafile file number=00004 name=/u01/app/oracle/oradata/orcl/undotbs01.dbf
input datafile file number=00006 name=/u01/app/oracle/oradata/orcl/users01.dbf
channel ORA_DISK_1: starting piece 1 at 10-JAN-18
channel ORA_DISK_1: finished piece 1 at 10-JAN-18
piece handle=/u01/app/oracle/fast_recovery_area/ORCL/backupset/2018_01_10/o1_mf_nnndf_TAG20180110T152135_f5crk7pb_.bkp tag=TAG20180110T152135 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:55
Finished backup at 10-JAN-18

Starting backup at 10-JAN-18
current log archived
using channel ORA_DISK_1
channel ORA_DISK_1: starting archived log backup set
channel ORA_DISK_1: specifying archived log(s) in backup set
input archived log thread=1 sequence=2 RECID=25 STAMP=965056950
channel ORA_DISK_1: starting piece 1 at 10-JAN-18
channel ORA_DISK_1: finished piece 1 at 10-JAN-18
piece handle=/u01/app/oracle/fast_recovery_area/ORCL/backupset/2018_01_10/o1_mf_annnn_TAG20180110T152230_f5crlyvl_.bkp tag=TAG20180110T152230 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
Finished backup at 10-JAN-18

Starting Control File and SPFILE Autobackup at 10-JAN-18
piece handle=/u01/app/oracle/fast_recovery_area/ORCL/autobackup/2018_01_10/o1_mf_s_965056952_f5crm0dh_.bkp comment=NONE

Finished Control File and SPFILE Autobackup at 10-JAN-18

ttestdb:/u02/oradata/testdb/TESTDB/autobackup/2018_01_10> ls -lrt

total 63040

-rw-r-----    1 oracle   dba         6455296 Jan  10  10:22 o1_mf_s_693915680_57dlgcqh_.bkp

-rw-r-----    1 oracle   dba         6455296 Jan   10  11:49 o1_mf_s_693920955_57dqkw0j_.bkp

-rw-r-----    1 oracle   dba         6455296 Jan   10  13:28 o1_mf_s_693926889_57dxcbdx_.bkp

-rw-r-----    1 oracle   dba         6455296 Jan   10  14:18 o1_mf_s_693928526_57f094n9_.bkp

-rw-r-----    1 oracle   dba         6455296 Jan    10  14:20 o1_mf_s_693930026_57f0fbo2_.bkp

When we drop the tablespace we are changing the structure of the database and since controlfile autobackup has been turned on, we see another backup file has been created in the autobackup location in the flash recovery area on disk.

Now we create tablespace..

SQL> create tablespace arul datafile '/u01/app/oracle/oradata/orcl/arul1.dbf'  
size 100M  extent management local;

SQL> drop tablespace arul including contents and datafiles;

Tablespace dropped.

Now We check valid backup

testdb:/u02/oradata/testdb/TESTDB/autobackup/2009_08_03> ls -lrt

total 75648

-rw-r-----    1 oracle   dba         6455296 Jan  10  10:22 o1_mf_s_693915680_57dlgcqh_.bkp

-rw-r-----    1 oracle   dba         6455296 Jan   10  11:49 o1_mf_s_693920955_57dqkw0j_.bkp

-rw-r-----    1 oracle   dba         6455296 Jan   10  3 13:28 o1_mf_s_693926889_57dxcbdx_.bkp

-rw-r-----    1 oracle   dba         6455296 Jan   10  14:18 o1_mf_s_693928526_57f094n9_.bkp

-rw-r-----    1 oracle   dba         6455296 Jan   10  14:20 o1_mf_s_693930026_57f0fbo2_.bkp

-rw-r-----    1 oracle   dba         6455296 Aug  3 14:38 o1_mf_s_693931114_57f1hbmo_.bkp

We then shutdown the database, startup in nomount mode and attempt to restore the controlfile from autobackup.

The most recent controlfile autobackup has been restored, but since this has been taken after the tablespace was dropped, the tablespace which has been dropped (ARUL) is not referenced in the control file that we just restored. If we try to restore and recover the database, the dropped tablespace will not be restored.

 SQL> shutdown immediate;

SQL> startup nomount;

ORACLE instance started.

Total System Global Area  264241152 bytes

Fixed Size                  2083304 bytes

Variable Size             142607896 bytes

Database Buffers          113246208 bytes

Redo Buffers                6303744 bytes

RMAN> restore controlfile from autobackup;

Starting restore at 10-JAN-18

using target database control file instead of recovery catalog

allocated channel: ORA_DISK_1

channel ORA_DISK_1: sid=156 devtype=DISK

recovery area destination: /u02/oradata/testdb/

database name (or database unique name) used for search: TESTDB

channel ORA_DISK_1: autobackup found in the recovery area

channel ORA_DISK_1: autobackup found: /u02/oradata/testdb/TESTDB/autobackup/2009_08_03/o1_mf_s_693931114_57f1hbmo_.bkp

channel ORA_DISK_1: control file restore from autobackup complete

output filename=/u02/oradata/testdb/control01.ctl

output filename=/u02/oradata/testdb/control02.ctl

output filename=/u02/oradata/testdb/control03.ctl

Finished restore at 10-JAN-18

RMAN> alter database mount;

database mounted

released channel: ORA_DISK_1

RMAN> report schema;

...

List of Permanent Datafiles

===========================

File Size(MB) Tablespace           RB segs Datafile Name

---- -------- -------------------- ------- ------------------------

1    1230     SYSTEM               ***     /u02/oradata/testdb/system01.dbf

2    1700     UNDOTBS1             ***     /u02/oradata/testdb/undotbs01.dbf

3    370      SYSAUX               ***     /u02/oradata/testdb/sysaux01.dbf

4    280      USERS                ***     /u02/oradata/backup/bkp.04klgv2b

5    131      EXAMPLE              ***     /u02/oradata/testdb/example01.dbf

6    150      USERS                ***     /u02/oradata/backup/bkp.06klgv3k

9    100      USERS                ***     /u02/oradata/backup/bkp.08klgv4i

We will need to restore a backup of the controlfile which contains records for the tablespace ARUL. We use the RESTORE CONTROLFILE FROM command to restore a specific controlfile autobackup.

RMAN>  restore controlfile from '/u02/oradata/testdb/TESTDB/autobackup/2018_01_10/o1_mf_s_693930026_57f0fbo2_.bkp';

Starting restore at 10-JAN-18

using channel ORA_DISK_1

channel ORA_DISK_1: restoring control file

channel ORA_DISK_1: restore complete, elapsed time: 00:00:02

output filename=/u02/oradata/testdb/control01.ctl

output filename=/u02/oradata/testdb/control02.ctl

output filename=/u02/oradata/testdb/control03.ctl

Finished restore at 10-JAN-18

RMAN> report schema;

.....

List of Permanent Datafiles

===========================

File Size(MB) Tablespace           RB segs Datafile Name

---- -------- -------------------- ------- ------------------------

1    1230     SYSTEM               ***     /u02/oradata/testdb/system01.dbf

2    1700     UNDOTBS1             ***     /u02/oradata/testdb/undotbs01.dbf

3    370      SYSAUX               ***     /u02/oradata/testdb/sysaux01.dbf

4    280      USERS                ***     /u02/oradata/backup/bkp.04klgv2b

5    131      EXAMPLE              ***     /u02/oradata/testdb/example01.dbf

6    150      USERS                ***     /u02/oradata/backup/bkp.06klgv3k

7    0        ARUL                 ***     /u02/oradata/testdb/arul01.dbf

9    100      USERS                ***     /u02/oradata/backup/bkp.08klgv4i

The alert log will also show the time when the tablespace was dropped. We can also see that a controlfile autobackup has taken place after the tablespace was dropped.

drop tablespace arul including contents and datafiles

Mon Jan  10 14:38:34 2018

Deleted file /u02/oradata/testdb/arul01.dbf

Starting control autobackup

Control autobackup written to DISK device

        handle '/u02/oradata/testdb/TESTDB/autobackup/2018_01_10/o1_mf_s_693931114_57f1hbmo_.bkp'

Completed: drop tablespace arul including contents and datafiles

Now that we know the time the tablespace was dropped, we can do a point in time recovery of the DATABASE in order to recover the tablespace which has been dropped.

RMAN> run {

2> set until time "to_date('10-JAN-2018 14:38:00','DD-MON-YYYY HH24:Mi:SS')";

3> restore database;

4> recover database;

5> }

executing command: SET until clause

using target database control file instead of recovery catalog

Starting restore at 10-JAN-18

allocated channel: ORA_SBT_TAPE_1

channel ORA_SBT_TAPE_1: sid=159 devtype=SBT_TAPE

channel ORA_SBT_TAPE_1: Data Protection for Oracle: version 5.5.1.0

allocated channel: ORA_DISK_1

channel ORA_DISK_1: sid=155 devtype=DISK

channel ORA_DISK_1: restoring datafile 00004

input datafile copy recid=14 stamp=693929215 filename=/u02/oradata/testdb/users01.dbf

destination for restore of datafile 00004: /u02/oradata/backup/bkp.04klgv2b

channel ORA_SBT_TAPE_1: starting datafile backupset restore

channel ORA_SBT_TAPE_1: specifying datafile(s) to restore from backup set

restoring datafile 00001 to /u02/oradata/testdb/system01.dbf

restoring datafile 00002 to /u02/oradata/testdb/undotbs01.dbf

restoring datafile 00003 to /u02/oradata/testdb/sysaux01.dbf

restoring datafile 00005 to /u02/oradata/testdb/example01.dbf

restoring datafile 00007 to /u02/oradata/testdb/arul01.dbf

channel ORA_SBT_TAPE_1: reading from backup piece 0gkloo6p_1_1

channel ORA_DISK_1: copied datafile copy of datafile 00004

output filename=/u02/oradata/backup/bkp.04klgv2b recid=21 stamp=693932732

channel ORA_DISK_1: restoring datafile 00006

input datafile copy recid=13 stamp=693929146 filename=/u02/oradata/testdb/users02.dbf

destination for restore of datafile 00006: /u02/oradata/backup/bkp.06klgv3k

channel ORA_DISK_1: copied datafile copy of datafile 00006

output filename=/u02/oradata/backup/bkp.06klgv3k recid=23 stamp=693932755

channel ORA_DISK_1: restoring datafile 00009

input datafile copy recid=10 stamp=693929108 filename=/u02/oradata/testdb/users03.dbf

destination for restore of datafile 00009: /u02/oradata/backup/bkp.08klgv4i

channel ORA_DISK_1: copied datafile copy of datafile 00009

output filename=/u02/oradata/backup/bkp.08klgv4i recid=26 stamp=693932809

channel ORA_SBT_TAPE_1: restored backup piece 1

piece handle=0gkloo6p_1_1 tag=TAG20090803T113241

channel ORA_SBT_TAPE_1: restore complete, elapsed time: 00:02:40

Finished restore at 10-JAN-18

Starting recover at 10-JAN-18

using channel ORA_SBT_TAPE_1

using channel ORA_DISK_1

starting media recovery

archive log thread 1 sequence 8 is already on disk as file /u02/oradata/testdb/arch/arch.8.1.693662800.log

archive log thread 1 sequence 9 is already on disk as file /u02/oradata/testdb/arch/arch.9.1.693662800.log

archive log thread 1 sequence 10 is already on disk as file /u02/oradata/testdb/arch/arch.10.1.693662800.log

archive log thread 1 sequence 1 is already on disk as file /u02/oradata/testdb/redo01.log

archive log thread 1 sequence 2 is already on disk as file /u02/oradata/testdb/redo02.log

archive log filename=/u02/oradata/testdb/arch/arch.8.1.693662800.log thread=1 sequence=8

archive log filename=/u02/oradata/testdb/arch/arch.9.1.693662800.log thread=1 sequence=9

archive log filename=/u02/oradata/testdb/arch/arch.10.1.693662800.log thread=1 sequence=10

archive log filename=/u02/oradata/testdb/redo01.log thread=1 sequence=1

archive log filename=/u02/oradata/testdb/redo02.log thread=1 sequence=2

media recovery complete, elapsed time: 00:00:06

Finished recover at 10-JAN-18

RMAN>

RMAN> alter database open resetlogs;

database opened

We can now see that the tablespace which has been dropped has been recovered

SQL> select file_name,bytes from dba_data_files where

  2  tablespace_name='ARUL';

FILE_NAME

--------------------------------------------------------------------------------

     BYTES

----------

/u02/oradata/testdb/arul01.dbf

  37748736