11g Release 2 Tablespace Point In Time Recovery – recover from dropped tablespace

One of the good new features in 11g Release 2 is that it enables us to recover from a case of a dropped tablespace. TSPITR (tablespace point in time recovery) has been around in earlier releases, but we could not recover a dropped tablespace.

What 11gR2 does is that it peforms a fully automated RMAN managed TSPITR. It creates and starts the auxiliary instance and restores just the datafiles it requires – SYSTEM,SYSAUX,UNDO and the files pertaining to the dropped tablespace – in this case datafiles 1,2,3 and 7- in the location which we specify as the ‘Auxiliary Destination’. It will first perform a recovery of the tablespace on the auxiliary instance and then use Data Pump and Transportable Tablespace technology to extract and import the tablespace meta data into the original source database.

To illustrate this example we create a new tablespace MYEXAMPLE and create two tables MYSALES and MYCOSTS in this tablespace. We take a database backup and then drop the tablespace and then perform tablespace point in time recovery using RMAN.

Before dropping the tablespace we first note the SCN as we will use this SCN when we do the TSPITR. Note also that we are connected to a RMAN catalog as well although the documentation does state that we can perform TSPITR without a recovery catalog.

SQL> create tablespace myexample datafile '+DATA' size 200m;

Tablespace created.

SQL> create table mysales
  2  tablespace myexample
  3  as select * from sales;

Table created.

SQL> create table mycosts
  2  tablespace myexample
  3   as select * from costs;

Table created.

SQL> conn / as sysdba
Connected.
SQL> alter system switch logfile;

System altered.

SQL> select current_scn from v$database;

CURRENT_SCN
-----------
    1043322

SQL> drop tablespace myexample including contents and datafiles;

Tablespace dropped.

RMAN> run {
2> set newname for datafile 7 to '+DATA';
3> recover tablespace myexample
4> until scn 1043322
5> auxiliary destination '+DATA';
6> }

executing command: SET NEWNAME

Starting recover at 27-NOV-09
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=137 device type=DISK

Creating automatic instance, with SID='qyBo'

initialization parameters used for automatic instance:
db_name=TESTDB
db_unique_name=qyBo_tspitr_TESTDB
compatible=11.2.0.0.0
db_block_size=8192
db_files=200
sga_target=280M
processes=50
db_create_file_dest=+DATA
log_archive_dest_1='location=+DATA'
#No auxiliary parameter file used


starting up automatic instance TESTDB

Oracle instance started

Total System Global Area     292278272 bytes

Fixed Size                     2212736 bytes
Variable Size                100666496 bytes
Database Buffers             184549376 bytes
Redo Buffers                   4849664 bytes
Automatic instance created

contents of Memory Script:
{
# set requested point in time
set until  scn 1043322;
# restore the controlfile
restore clone controlfile;
# mount the controlfile
sql clone 'alter database mount clone database';
# archive current online log
sql 'alter system archive log current';
# avoid unnecessary autobackups for structural changes during TSPITR
sql 'begin dbms_backup_restore.AutoBackupFlag(FALSE); end;';
# resync catalog
resync catalog;
}
executing Memory Script

executing command: SET until clause

Starting restore at 27-NOV-09
allocated channel: ORA_AUX_DISK_1
channel ORA_AUX_DISK_1: SID=81 device type=DISK

channel ORA_AUX_DISK_1: starting datafile backup set restore
channel ORA_AUX_DISK_1: restoring control file
channel ORA_AUX_DISK_1: reading from backup piece +DATA/testdb/backupset/2009_11_27/ncsnf0_tag20091127t104307_0.502.
704025815
channel ORA_AUX_DISK_1: piece handle=+DATA/testdb/backupset/2009_11_27/ncsnf0_tag20091127t104307_0.502.
704025815 tag=TAG20091127T104307
channel ORA_AUX_DISK_1: restored backup piece 1
channel ORA_AUX_DISK_1: restore complete, elapsed time: 00:00:04
output file name=+DATA/testdb/controlfile/current.506.704033345
Finished restore at 27-NOV-09

sql statement: alter database mount clone database

sql statement: alter system archive log current

sql statement: begin dbms_backup_restore.AutoBackupFlag(FALSE); end;

starting full resync of recovery catalog
full resync complete

contents of Memory Script:
{
# set requested point in time
set until  scn 1043322;
# set destinations for recovery set and auxiliary set datafiles
set newname for clone datafile  1 to new;
set newname for clone datafile  3 to new;
set newname for clone datafile  2 to new;
set newname for clone tempfile  1 to new;
set newname for datafile  7 to
 "+DATA";
# switch all tempfiles
switch clone tempfile all;
# restore the tablespaces in the recovery set and the auxiliary set
restore clone datafile  1, 3, 2, 7;
switch clone datafile all;
}
executing Memory Script

executing command: SET until clause

executing command: SET NEWNAME

executing command: SET NEWNAME

executing command: SET NEWNAME

executing command: SET NEWNAME

executing command: SET NEWNAME

renamed tempfile 1 to +DATA in control file

Starting restore at 27-NOV-09
using channel ORA_AUX_DISK_1

channel ORA_AUX_DISK_1: starting datafile backup set restore
channel ORA_AUX_DISK_1: specifying datafile(s) to restore from backup set
channel ORA_AUX_DISK_1: restoring datafile 00001 to +DATA
channel ORA_AUX_DISK_1: restoring datafile 00003 to +DATA
channel ORA_AUX_DISK_1: restoring datafile 00002 to +DATA
channel ORA_AUX_DISK_1: restoring datafile 00007 to +DATA
channel ORA_AUX_DISK_1: reading from backup piece +DATA/testdb/backupset/2009_11_27/nnndf0_tag20091127t104307 .....
channel ORA_AUX_DISK_1: piece handle=+DATA/testdb/backupset/2009_11_27/nnndf0_tag20091127t104307_0.501.
704025789 tag=TAG200 .........
channel ORA_AUX_DISK_1: restored backup piece 1
channel ORA_AUX_DISK_1: restore complete, elapsed time: 00:00:26
Finished restore at 27-NOV-09

datafile 7 switched to datafile copy
input datafile copy RECID=6 STAMP=704033380 file name=+DATA/testdb/datafile/myexample.512.
704033355
datafile 1 switched to datafile copy
input datafile copy RECID=7 STAMP=704033380 file name=+DATA/testdb/datafile/system.511.
704033355
datafile 3 switched to datafile copy
input datafile copy RECID=8 STAMP=704033380 file name=+DATA/testdb/datafile/undotbs1.513.
704033355
datafile 2 switched to datafile copy
input datafile copy RECID=9 STAMP=704033380 file name=+DATA/testdb/datafile/sysaux.509.
704033355

contents of Memory Script:
{
# set requested point in time
set until  scn 1043322;
# online the datafiles restored or switched
sql clone "alter database datafile  1 online";
sql clone "alter database datafile  3 online";
sql clone "alter database datafile  2 online";
sql clone "alter database datafile  7 online";
# recover and open resetlogs
recover clone database tablespace  "MYEXAMPLE", "SYSTEM", "UNDOTBS1", "SYSAUX" delete archivelog;
alter clone database open resetlogs;
}
executing Memory Script

executing command: SET until clause

sql statement: alter database datafile  1 online

sql statement: alter database datafile  3 online

sql statement: alter database datafile  2 online

sql statement: alter database datafile  7 online

Starting recover at 27-NOV-09
using channel ORA_AUX_DISK_1

starting media recovery

archived log for thread 1 with sequence 10 is already on disk as file +DATA/testdb/archivelog/2009_11_27/.....
archived log for thread 1 with sequence 11 is already on disk as file +DATA/testdb/archivelog/2009_11_27/.....
archived log for thread 1 with sequence 12 is already on disk as file +DATA/testdb/archivelog/2009_11_27/ ......
archived log file name=+DATA/testdb/archivelog/2009_11_27/ ....
archived log file name=+DATA/testdb/archivelog/2009_11_27/....
archived log file name=+DATA/testdb/archivelog/2009_11_27/....
media recovery complete, elapsed time: 00:00:01
Finished recover at 27-NOV-09

database opened

contents of Memory Script:
{
# make read only the tablespace that will be exported
sql clone 'alter tablespace  MYEXAMPLE read only';
# create directory for datapump import
sql "create or replace directory TSPITR_DIROBJ_DPDIR as ''
+DATA''";
# create directory for datapump export
sql clone "create or replace directory TSPITR_DIROBJ_DPDIR as ''
+DATA''";
}
executing Memory Script

sql statement: alter tablespace  MYEXAMPLE read only

sql statement: create or replace directory TSPITR_DIROBJ_DPDIR as ''+DATA''

sql statement: create or replace directory TSPITR_DIROBJ_DPDIR as ''+DATA''

Performing export of metadata...

   EXPDP> Starting "SYS"."TSPITR_EXP_qyBo":
   EXPDP> Processing object type TRANSPORTABLE_EXPORT/PLUGTS_BLK
   EXPDP> Processing object type TRANSPORTABLE_EXPORT/TABLE
   EXPDP> Processing object type TRANSPORTABLE_EXPORT/POST_INSTANCE/PLUGTS_BLK
   EXPDP> Master table "SYS"."TSPITR_EXP_qyBo" successfully loaded/unloaded
   EXPDP> ******************************************************************************
   EXPDP> Dump file set for SYS.TSPITR_EXP_qyBo is:
   EXPDP>   +DATA/tspitr_qybo_53647.dmp
   EXPDP> ******************************************************************************
   EXPDP> Datafiles required for transportable tablespace MYEXAMPLE:
   EXPDP>   +DATA/testdb/datafile/myexample.512.704033355
   EXPDP> Job "SYS"."TSPITR_EXP_qyBo" successfully completed at 12:51:34
Export completed


contents of Memory Script:
{
# shutdown clone before import
shutdown clone immediate
}
executing Memory Script

database closed
database dismounted
Oracle instance shut down

Performing import of metadata...
   IMPDP> Master table "SYS"."TSPITR_IMP_qyBo" successfully loaded/unloaded
   IMPDP> Starting "SYS"."TSPITR_IMP_qyBo":
   IMPDP> Processing object type TRANSPORTABLE_EXPORT/PLUGTS_BLK
   IMPDP> Processing object type TRANSPORTABLE_EXPORT/TABLE
   IMPDP> Processing object type TRANSPORTABLE_EXPORT/POST_INSTANCE/PLUGTS_BLK
   IMPDP> Job "SYS"."TSPITR_IMP_qyBo" successfully completed at 12:51:49
Import completed


contents of Memory Script:
{
# make read write and offline the imported tablespaces
sql 'alter tablespace  MYEXAMPLE read write';
sql 'alter tablespace  MYEXAMPLE offline';
# enable autobackups after TSPITR is finished
sql 'begin dbms_backup_restore.AutoBackupFlag(TRUE); end;';
# resync catalog
resync catalog;
}
executing Memory Script

sql statement: alter tablespace  MYEXAMPLE read write

sql statement: alter tablespace  MYEXAMPLE offline

sql statement: begin dbms_backup_restore.AutoBackupFlag(TRUE); end;

starting full resync of recovery catalog
full resync complete

Removing automatic instance
Automatic instance removed
auxiliary instance file +DATA/testdb/tempfile/temp.518.704033385 deleted
auxiliary instance file +DATA/testdb/onlinelog/group_3.517.704033385 deleted
auxiliary instance file +DATA/testdb/onlinelog/group_2.515.704033383 deleted
auxiliary instance file +DATA/testdb/onlinelog/group_1.514.704033383 deleted
auxiliary instance file +DATA/testdb/datafile/sysaux.509.704033355 deleted
auxiliary instance file +DATA/testdb/datafile/undotbs1.513.704033355 deleted
auxiliary instance file +DATA/testdb/datafile/system.511.704033355 deleted
auxiliary instance file +DATA/testdb/controlfile/current.506.704033345 deleted
Finished recover at 27-NOV-09

RMAN>

Note: After the recovery is complete, we need to bring the tablespace and datafile online as well.

SQL> alter tablespace myexample online;

Tablespace altered.

SQL> alter database datafile '+DATA/testdb/datafile/myexample.512.704033355' online;

Database altered.

SQL> select file_name from dba_data_files where tablespace_name='MYEXAMPLE';

FILE_NAME
--------------------------------------------------------------------------------
+DATA/testdb/datafile/myexample.512.704033355

SQL> select table_name from dba_tables
  2  where tablespace_name='MYEXAMPLE';

TABLE_NAME
------------------------------
MYSALES
MYCOSTS

SQL> select count(*) from sh.mysales;

  COUNT(*)
----------
    918843