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In this article we are going to see datafile recovery when no backup exists and lost a datafile at the OS level and there are no current backups. we are in archivelog mode. we have all Archivelogs available since the datafile was created initially .We must have RMAN full backup and archivelogs to recover the datafile when no recent backup of datafile exists.
Step 1: New tablespace creation
SQL> startup
ORACLE instance started.
Total System Global Area 3019895280 bytes
Fixed Size 8901104 bytes
Variable Size 738197504 bytes
Database Buffers 2264924160 bytes
Redo Buffers 7872512 bytes
Database mounted.
Database opened.
SQL> create tablespace inba datafile ‘/u01/app/oracle/oradata/INBAA/inba_01.dbf’ size 10m;
SQL> select file_name from dba_data_files where tablespace_name=’INBA’;
FILE_NAME
/u01/app/oracle/oradata/INBAA/inba_01.dbf
Step 2: Take RMAN whole database backup and plus archivelog
[oracle@localhost scripts]$ . ora19c.env
[oracle@localhost scripts]$ rman target /
Recovery Manager: Release 19.0.0.0.0 – Production on Sun Jan 31 14:06:59 2021
Version 19.10.0.0.0
Copyright (c) 1982, 2019, Oracle and/or its affiliates. All rights reserved.
connected to target database: INBAA (DBID=936024966)
RMAN> backup database plus archivelog;
Starting backup at 31-JAN-21
current log archived
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=80 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=7 RECID=7 STAMP=1063046546
input archived log thread=1 sequence=8 RECID=8 STAMP=1063046565
input archived log thread=1 sequence=9 RECID=9 STAMP=1063046590
channel ORA_DISK_1: starting piece 1 at 31-JAN-21
channel ORA_DISK_1: finished piece 1 at 31-JAN-21
piece handle=/u01/app/oracle/recovery_area/INBAA/backupset/2021_01_31/o1_mf_annnn_TAG20210131T140939_j1dv6d6n_.bkp tag=TAG20210131T140939 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:25
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=21 STAMP=1063286511
channel ORA_DISK_1: starting piece 1 at 31-JAN-21
channel ORA_DISK_1: finished piece 1 at 31-JAN-21
piece handle=/u01/app/oracle/recovery_area/INBAA/backupset/2021_01_31/o1_mf_annnn_TAG20210131T140939_j1dv75db_.bkp tag=TAG20210131T140939 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:03
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=16 STAMP=1063051981
channel ORA_DISK_1: starting piece 1 at 31-JAN-21
channel ORA_DISK_1: finished piece 1 at 31-JAN-21
piece handle=/u01/app/oracle/recovery_area/INBAA/backupset/2021_01_31/o1_mf_annnn_TAG20210131T140939_j1dv78jp_.bkp tag=TAG20210131T140939 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=1 RECID=11 STAMP=1063048762
input archived log thread=1 sequence=2 RECID=12 STAMP=1063048795
input archived log thread=1 sequence=3 RECID=13 STAMP=1063048814
channel ORA_DISK_1: starting piece 1 at 31-JAN-21
channel ORA_DISK_1: finished piece 1 at 31-JAN-21
piece handle=/u01/app/oracle/recovery_area/INBAA/backupset/2021_01_31/o1_mf_annnn_TAG20210131T140939_j1dv79no_.bkp tag=TAG20210131T140939 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=1 RECID=22 STAMP=1063289379
channel ORA_DISK_1: starting piece 1 at 31-JAN-21
channel ORA_DISK_1: finished piece 1 at 31-JAN-21
piece handle=/u01/app/oracle/recovery_area/INBAA/backupset/2021_01_31/o1_mf_annnn_TAG20210131T140939_j1dv7bs0_.bkp tag=TAG20210131T140939 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=1 RECID=14 STAMP=1063049415
channel ORA_DISK_1: starting piece 1 at 31-JAN-21
channel ORA_DISK_1: finished piece 1 at 31-JAN-21
piece handle=/u01/app/oracle/recovery_area/INBAA/backupset/2021_01_31/o1_mf_annnn_TAG20210131T140939_j1dv7cxv_.bkp tag=TAG20210131T140939 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=4 RECID=15 STAMP=1063049564
channel ORA_DISK_1: starting piece 1 at 31-JAN-21
channel ORA_DISK_1: finished piece 1 at 31-JAN-21
piece handle=/u01/app/oracle/recovery_area/INBAA/backupset/2021_01_31/o1_mf_annnn_TAG20210131T140939_j1dv7f31_.bkp tag=TAG20210131T140939 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=2 RECID=17 STAMP=1063051985
channel ORA_DISK_1: starting piece 1 at 31-JAN-21
channel ORA_DISK_1: finished piece 1 at 31-JAN-21
piece handle=/u01/app/oracle/recovery_area/INBAA/backupset/2021_01_31/o1_mf_annnn_TAG20210131T140939_j1dv7g7b_.bkp tag=TAG20210131T140939 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
Finished backup at 31-JAN-21
Starting backup at 31-JAN-21
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=00001 name=/u01/app/oracle/oradata/INBAA/system01.dbf
input datafile file number=00003 name=/u01/app/oracle/oradata/INBAA/sysaux01.dbf
input datafile file number=00004 name=/u01/app/oracle/oradata/INBAA/undotbs01.dbf
input datafile file number=00005 name=/u01/app/oracle/oradata/INBAA/inba_01.dbf
input datafile file number=00007 name=/u01/app/oracle/oradata/INBAA/users01.dbf
channel ORA_DISK_1: starting piece 1 at 31-JAN-21
channel ORA_DISK_1: finished piece 1 at 31-JAN-21
piece handle=/u01/app/oracle/recovery_area/INBAA/backupset/2021_01_31/o1_mf_nnndf_TAG20210131T141015_j1dv7ho6_.bkp tag=TAG20210131T141015 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:45
Finished backup at 31-JAN-21
Starting backup at 31-JAN-21
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=23 STAMP=1063289460
channel ORA_DISK_1: starting piece 1 at 31-JAN-21
channel ORA_DISK_1: finished piece 1 at 31-JAN-21
piece handle=/u01/app/oracle/recovery_area/INBAA/backupset/2021_01_31/o1_mf_annnn_TAG20210131T141100_j1dv8wxp_.bkp tag=TAG20210131T141100 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
Finished backup at 31-JAN-21
Starting Control File and SPFILE Autobackup at 31-JAN-21
piece handle=/u01/app/oracle/recovery_area/INBAA/autobackup/2021_01_31/o1_mf_s_1063289462_j1dv8yop_.bkp comment=NONE
Finished Control File and SPFILE Autobackup at 31-JAN-21
RMAN>
Step 3: Add a New Datafile to that Tablespace and verify that the new file is now a member of the tablespace.
SQL> alter tablespace inba add datafile ‘/u01/app/oracle/oradata/INBAA/inba_02.dbf’ size 10m;
Tablespace altered.
SQL> select file_name from dba_data_files where tablespace_name like ‘INBA’;
SQL> alter system switch logfile;
System altered.
SQL> /
System altered.
SQL> /
System altered.
SQL>
Step 4: Create a ‘emp’ table in that tablespace and perform some DML operation. Also after DML operations switch some logfile.
SQL> create table emp(id number) tablespace inba;
Table created.
SQL> insert into emp values(11);
1 row created.
SQL> insert into emp values(12);
1 row created.
SQL> insert into emp values(13);
1 row created.
SQL> insert into emp values(14);
1 row created.
SQL> insert into emp values(15);
1 row created.
SQL> select * from emp;
Step 5: In the OS Level,remove all files of that “INBA” tablespace including the newly added one (whose backup does not exist).
Step 6:- Try to bring the tablespace offline and we will get error message as follows
SQL> alter tablespace inba offline;
Tablespace altered.
Step 7: Check the status of tablespace and file_id of datafiles
SQL> select TABLESPACE_NAME,STATUS from dba_tablespaces;
TABLESPACE_NAME STATUS
—————————— ———
SYSTEM ONLINE
SYSAUX ONLINE
UNDOTBS1 ONLINE
TEMP ONLINE
USERS ONLINE
INBA OFFLINE
6 rows selected.
SQL> select file_id,file_name from dba_data_files where tablespace_name like ‘INBA’;
BS Key Type LV Size Device Type Elapsed Time Completion Time
22 Full 1.32G DISK 00:00:37 31-JAN-21
BP Key: 22 Status: AVAILABLE Compressed: NO Tag: TAG20210131T141015
Piece Name: /u01/app/oracle/recovery_area/INBAA/backupset/2021_01_31/o1_mf_nnndf_TAG20210131T141015_j1dv7ho6_.bkp
List of Datafiles in backup set 22
File LV Type Ckp SCN Ckp Time Abs Fuz SCN Sparse Name
5 Full 2392081 31-JAN-21 NO /u01/app/oracle/oradata/INBAA/inba_01.dbf
RMAN> list backup of datafile 2;
specification does not match any backup in the repository
RMAN>
Now connect to RMAN and confirm that no backup exists for the newly added datafile FILE_ID 2. Then try to restore the DBWRTBS tablespace, RMAN will create that newly added datafile as a part of the restore process.
Step 9: Tablespace restore
RMAN> restore tablespace inba;
Starting restore at 31-JAN-21
using channel ORA_DISK_1
creating datafile file number=2 name=/u01/app/oracle/oradata/INBAA/inba_02.dbf
channel ORA_DISK_1: starting datafile backup set restore
channel ORA_DISK_1: specifying datafile(s) to restore from backup set
channel ORA_DISK_1: restoring datafile 00005 to /u01/app/oracle/oradata/INBAA/inba_01.dbf
channel ORA_DISK_1: reading from backup piece /u01/app/oracle/recovery_area/INBAA/backupset/2021_01_31/o1_mf_nnndf_TAG20210131T141015_j1dv7ho6_.bkp
channel ORA_DISK_1: piece handle=/u01/app/oracle/recovery_area/INBAA/backupset/2021_01_31/o1_mf_nnndf_TAG20210131T141015_j1dv7ho6_.bkp tag=TAG20210131T141015
channel ORA_DISK_1: restored backup piece 1
channel ORA_DISK_1: restore complete, elapsed time: 00:00:01
Finished restore at 31-JAN-21
RMAN>
Step 10: Recover tablespace
RMAN> recover tablespace inba;
Starting recover at 31-JAN-21
using channel ORA_DISK_1
starting media recovery
archived log for thread 1 with sequence 2 is already on disk as file /u01/app/oracle/recovery_area/INBAA/archivelog/2021_01_31/o1_mf_1_2_j1dv8wp0_.arc
archived log for thread 1 with sequence 3 is already on disk as file /u01/app/oracle/recovery_area/INBAA/archivelog/2021_01_31/o1_mf_1_3_j1dvhzjx_.arc
archived log for thread 1 with sequence 4 is already on disk as file /u01/app/oracle/recovery_area/INBAA/archivelog/2021_01_31/o1_mf_1_4_j1dvj2t2_.arc
archived log for thread 1 with sequence 5 is already on disk as file /u01/app/oracle/recovery_area/INBAA/archivelog/2021_01_31/o1_mf_1_5_j1dvj585_.arc
archived log file name=/u01/app/oracle/recovery_area/INBAA/archivelog/2021_01_31/o1_mf_1_2_j1dv8wp0_.arc thread=1 sequence=2
archived log file name=/u01/app/oracle/recovery_area/INBAA/archivelog/2021_01_31/o1_mf_1_3_j1dvhzjx_.arc thread=1 sequence=3
media recovery complete, elapsed time: 00:00:00
Finished recover at 31-JAN-21
RMAN>
Step 11: To Bring the Tablespace online
SQL> alter tablespace inba online;
Tablespace altered.
SQL> select TABLESPACE_NAME,STATUS from dba_tablespaces;
Step 12: After the tablespace recovery to take a Full Database Backup.
RMAN> backup database plus archivelog;
Starting backup at 31-JAN-21
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=7 RECID=7 STAMP=1063046546
input archived log thread=1 sequence=8 RECID=8 STAMP=1063046565
input archived log thread=1 sequence=9 RECID=9 STAMP=1063046590
channel ORA_DISK_1: starting piece 1 at 31-JAN-21
channel ORA_DISK_1: finished piece 1 at 31-JAN-21
piece handle=/u01/app/oracle/recovery_area/INBAA/backupset/2021_01_31/o1_mf_annnn_TAG20210131T143642_j1dws2lk_.bkp tag=TAG20210131T143642 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:25
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=21 STAMP=1063286511
channel ORA_DISK_1: starting piece 1 at 31-JAN-21
channel ORA_DISK_1: finished piece 1 at 31-JAN-21
piece handle=/u01/app/oracle/recovery_area/INBAA/backupset/2021_01_31/o1_mf_annnn_TAG20210131T143642_j1dwsvv2_.bkp tag=TAG20210131T143642 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:03
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=22 STAMP=1063289379
input archived log thread=1 sequence=2 RECID=23 STAMP=1063289460
input archived log thread=1 sequence=3 RECID=24 STAMP=1063289687
input archived log thread=1 sequence=4 RECID=25 STAMP=1063289690
input archived log thread=1 sequence=5 RECID=26 STAMP=1063289693
input archived log thread=1 sequence=6 RECID=27 STAMP=1063291002
channel ORA_DISK_1: starting piece 1 at 31-JAN-21
channel ORA_DISK_1: finished piece 1 at 31-JAN-21
piece handle=/u01/app/oracle/recovery_area/INBAA/backupset/2021_01_31/o1_mf_annnn_TAG20210131T143642_j1dwsz03_.bkp tag=TAG20210131T143642 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:02
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=16 STAMP=1063051981
channel ORA_DISK_1: starting piece 1 at 31-JAN-21
channel ORA_DISK_1: finished piece 1 at 31-JAN-21
piece handle=/u01/app/oracle/recovery_area/INBAA/backupset/2021_01_31/o1_mf_annnn_TAG20210131T143642_j1dwt03o_.bkp tag=TAG20210131T143642 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=1 RECID=11 STAMP=1063048762
input archived log thread=1 sequence=2 RECID=12 STAMP=1063048795
input archived log thread=1 sequence=3 RECID=13 STAMP=1063048814
channel ORA_DISK_1: starting piece 1 at 31-JAN-21
channel ORA_DISK_1: finished piece 1 at 31-JAN-21
piece handle=/u01/app/oracle/recovery_area/INBAA/backupset/2021_01_31/o1_mf_annnn_TAG20210131T143642_j1dwt18o_.bkp tag=TAG20210131T143642 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=1 RECID=14 STAMP=1063049415
channel ORA_DISK_1: starting piece 1 at 31-JAN-21
channel ORA_DISK_1: finished piece 1 at 31-JAN-21
piece handle=/u01/app/oracle/recovery_area/INBAA/backupset/2021_01_31/o1_mf_annnn_TAG20210131T143642_j1dwt2dh_.bkp tag=TAG20210131T143642 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=4 RECID=15 STAMP=1063049564
channel ORA_DISK_1: starting piece 1 at 31-JAN-21
channel ORA_DISK_1: finished piece 1 at 31-JAN-21
piece handle=/u01/app/oracle/recovery_area/INBAA/backupset/2021_01_31/o1_mf_annnn_TAG20210131T143642_j1dwt3k2_.bkp tag=TAG20210131T143642 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=2 RECID=17 STAMP=1063051985
channel ORA_DISK_1: starting piece 1 at 31-JAN-21
channel ORA_DISK_1: finished piece 1 at 31-JAN-21
piece handle=/u01/app/oracle/recovery_area/INBAA/backupset/2021_01_31/o1_mf_annnn_TAG20210131T143642_j1dwt4nt_.bkp tag=TAG20210131T143642 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
Finished backup at 31-JAN-21
Starting backup at 31-JAN-21
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=00001 name=/u01/app/oracle/oradata/INBAA/system01.dbf
input datafile file number=00003 name=/u01/app/oracle/oradata/INBAA/sysaux01.dbf
input datafile file number=00004 name=/u01/app/oracle/oradata/INBAA/undotbs01.dbf
input datafile file number=00002 name=/u01/app/oracle/oradata/INBAA/inba_02.dbf
input datafile file number=00005 name=/u01/app/oracle/oradata/INBAA/inba_01.dbf
input datafile file number=00007 name=/u01/app/oracle/oradata/INBAA/users01.dbf
channel ORA_DISK_1: starting piece 1 at 31-JAN-21
channel ORA_DISK_1: finished piece 1 at 31-JAN-21
piece handle=/u01/app/oracle/recovery_area/INBAA/backupset/2021_01_31/o1_mf_nnndf_TAG20210131T143717_j1dwt60r_.bkp tag=TAG20210131T143717 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:01:06
Finished backup at 31-JAN-21
Starting backup at 31-JAN-21
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=7 RECID=28 STAMP=1063291103
channel ORA_DISK_1: starting piece 1 at 31-JAN-21
channel ORA_DISK_1: finished piece 1 at 31-JAN-21
piece handle=/u01/app/oracle/recovery_area/INBAA/backupset/2021_01_31/o1_mf_annnn_TAG20210131T143823_j1dww7b5_.bkp tag=TAG20210131T143823 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
Finished backup at 31-JAN-21
Starting Control File and SPFILE Autobackup at 31-JAN-21
piece handle=/u01/app/oracle/recovery_area/INBAA/autobackup/2021_01_31/o1_mf_s_1063291104_j1dwwbyt_.bkp comment=NONE
Finished Control File and SPFILE Autobackup at 31-JAN-21
RMAN>
Step 13: Now we have an complete RMAN backups which we newly added.
RMAN> list backup of datafile 5;
List of Backup Sets
===================
BS Key Type LV Size Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ ---------------
22 Full 1.32G DISK 00:00:37 31-JAN-21
BP Key: 22 Status: AVAILABLE Compressed: NO Tag: TAG20210131T141015
Piece Name: /u01/app/oracle/recovery_area/INBAA/backupset/2021_01_31/o1_mf_nnndf_TAG20210131T141015_j1dv7ho6_.bkp
List of Datafiles in backup set 22
File LV Type Ckp SCN Ckp Time Abs Fuz SCN Sparse Name
---- -- ---- ---------- --------- ----------- ------ ----
5 Full 2392081 31-JAN-21 NO /u01/app/oracle/oradata/INBAA/inba_01.dbf
BS Key Type LV Size Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ ---------------
35 Full 1.33G DISK 00:00:57 31-JAN-21
BP Key: 35 Status: AVAILABLE Compressed: NO Tag: TAG20210131T143717
Piece Name: /u01/app/oracle/recovery_area/INBAA/backupset/2021_01_31/o1_mf_nnndf_TAG20210131T143717_j1dwt60r_.bkp
List of Datafiles in backup set 35
File LV Type Ckp SCN Ckp Time Abs Fuz SCN Sparse Name
---- -- ---- ---------- --------- ----------- ------ ----
5 Full 2394449 31-JAN-21 NO /u01/app/oracle/oradata/INBAA/inba_01.dbf
RMAN> list backup of datafile 2;
List of Backup Sets
===================
BS Key Type LV Size Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ ---------------
35 Full 1.33G DISK 00:00:57 31-JAN-21
BP Key: 35 Status: AVAILABLE Compressed: NO Tag: TAG20210131T143717
Piece Name: /u01/app/oracle/recovery_area/INBAA/backupset/2021_01_31/o1_mf_nnndf_TAG20210131T143717_j1dwt60r_.bkp
List of Datafiles in backup set 35
File LV Type Ckp SCN Ckp Time Abs Fuz SCN Sparse Name
---- -- ---- ---------- --------- ----------- ------ ----
2 Full 2394449 31-JAN-21 NO /u01/app/oracle/oradata/INBAA/inba_02.dbf
RMAN>
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In this article we are going to see RMAN recovery through RESETLOGS.
What does a RESETLOGS do?
Archives the current online redo logs (if they are accessible) and then erases the contents of the online redo logs and resets the log sequence number to 1.
Creates the online redo log files if they do not currently exist.
Updates all current datafiles and online redo logs and all subsequent archived redo logs with a new RESETLOGS SCN and time stamp.
The Recovery through Resetlogs feature provides the following benefits:
There is no need to perform a full backup after an incomplete recovery.There is no need to recreate a new standby database after a failover operation.
You can take incremental backups based on full backups of a previous incarnation when you use RMAN.
Block media recovery can restore backups from parent incarnation backups and recover the corrupted blocks through a RESETLOGS operation.
You can use the newly generated logs with an earlier incarnation of the database.
Step 1:- Check the log_archive format as ‘%r’
SQL> show parameter log_archive_format
Note : To perform recovery through RESETLOGS you must have all archived logs generated after the most recent backup. The database would not start if you remove the %r from the log archive format specification.
Oracle 10g introduces a new format specification for archived log files. This new format avoids overwriting archived redo log files with the same sequence number across incarnations.The format specification of the log_archive_format string “%”r represents the resetlogs id. It will ensure that a unique name is constructed for the archived redo log file during RMAN restore and as well as restoring via SQL*plus auto recovery mode.
What is an incarnation?
A database incarnation is created whenever you open the database with the RESETLOGS option.
The Current incarnation is the one in which the database is running at present
The incarnation from which the current incarnation branched after a ALTER DATABASE OPEN RESETLOGS was performed is called the Parent incarnation.
If you want to go back to some SCN which is not part of the Current database incarnation, we need to use the RESET DATABASE TO INCARNATION
command as shown in the example below
Step 2:-Let us check what the current incarnation of the database
[oracle@localhost scripts]$ rman target /
Recovery Manager: Release 19.0.0.0.0 – Production on Sun Jan 31 18:39:21 2021
Version 19.10.0.0.0
Copyright (c) 1982, 2019, Oracle and/or its affiliates. All rights reserved.
connected to target database: INBAA (DBID=936024966)
RMAN> list incarnation of database;
using target database control file instead of recovery catalog
List of Database Incarnations
DB Key Inc Key DB Name DB ID STATUS Reset SCN Reset Time
Step 4:- Now, let us make a change in the database which we will then try to undo by restoring and recovering the database to a point in time before the media failure or as in this case, a wrong transaction has happened.
Simulate the wrong DML execution,
SQL> conn inba/inba
Connected.
SQL> create table student(id number);
Table created.
SQL> begin
for i in 1 .. 100000 loop
insert into student values(1);
end loop;
end;
/
SQL> select count(*) from student;
COUNT(*)
100000
SQL> delete from student where rownum < 1001;
1000 rows deleted.
SQL> commit;
Commit complete.
SQL> select count(*) from student;
Recovery Manager: Release 19.0.0.0.0 – Production on Sun Jan 31 18:48:55 2021
Version 19.10.0.0.0
Copyright (c) 1982, 2019, Oracle and/or its affiliates. All rights reserved.
connected to target database: INBAA (DBID=936024966, not open)
RMAN> run
{
set until scn 2406389;
restore database;
recover database;
}2> 3> 4> 5> 6>
executing command: SET until clause
Starting restore at 31-JAN-21
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=46 device type=DISK
channel ORA_DISK_1: starting datafile backup set restore
channel ORA_DISK_1: specifying datafile(s) to restore from backup set
channel ORA_DISK_1: restoring datafile 00001 to /u01/app/oracle/oradata/INBAA/system01.dbf
channel ORA_DISK_1: restoring datafile 00002 to /u01/app/oracle/oradata/INBAA/inba_02.dbf
channel ORA_DISK_1: restoring datafile 00003 to /u01/app/oracle/oradata/INBAA/sysaux01.dbf
channel ORA_DISK_1: restoring datafile 00004 to /u01/app/oracle/oradata/INBAA/undotbs01.dbf
channel ORA_DISK_1: restoring datafile 00005 to /u01/app/oracle/oradata/INBAA/inba_01.dbf
channel ORA_DISK_1: restoring datafile 00007 to /u01/app/oracle/oradata/INBAA/users01.dbf
channel ORA_DISK_1: reading from backup piece /u01/app/oracle/recovery_area/INBAA/backupset/2021_01_31/o1_mf_nnndf_TAG20210131T143717_j1dwt60r_.bkp
channel ORA_DISK_1: piece handle=/u01/app/oracle/recovery_area/INBAA/backupset/2021_01_31/o1_mf_nnndf_TAG20210131T143717_j1dwt60r_.bkp tag=TAG20210131T143717
channel ORA_DISK_1: restored backup piece 1
channel ORA_DISK_1: restore complete, elapsed time: 00:00:25
Finished restore at 31-JAN-21
Starting recover at 31-JAN-21
using channel ORA_DISK_1
starting media recovery
archived log for thread 1 with sequence 7 is already on disk as file /u01/app/oracle/recovery_area/INBAA/archivelog/2021_01_31/o1_mf_1_7_j1dww74c_.arc
archived log for thread 1 with sequence 8 is already on disk as file /u01/app/oracle/recovery_area/INBAA/archivelog/2021_01_31/o1_mf_1_8_j1f4jhv9_.arc
archived log for thread 1 with sequence 1 is already on disk as file /u01/app/oracle/recovery_area/INBAA/archivelog/2021_01_31/o1_mf_1_1_j1f6hkwh_.arc
archived log file name=/u01/app/oracle/recovery_area/INBAA/archivelog/2021_01_31/o1_mf_1_7_j1dww74c_.arc thread=1 sequence=7
archived log file name=/u01/app/oracle/recovery_area/INBAA/archivelog/2021_01_31/o1_mf_1_8_j1f4jhv9_.arc thread=1 sequence=8
archived log file name=/u01/app/oracle/recovery_area/INBAA/archivelog/2021_01_31/o1_mf_1_1_j1f6hkwh_.arc thread=1 sequence=1
media recovery complete, elapsed time: 00:00:07
Finished recover at 31-JAN-21
RMAN>
Step 7:- After open resetlogs,check the table count. We can now see that the deleted rows have been recovered and the number of rows in the table is now the same as before the delete operation was performed.
RMAN> alter database open resetlogs;
SQL> select count(*) from inba.student;
COUNT(*)
100000
Step 8:- Now let us check what the incarnation of the database,
RMAN> list incarnation of database;
List of Database Incarnations
DB Key Inc Key DB Name DB ID STATUS Reset SCN Reset Time
Step 10:- Set the SCN number of incarnation 10 and try to restore & recover the database
RMAN> run
{
set until scn 2406389;
restore database;
recover database;
}2> 3> 4> 5> 6>
executing command: SET until clause
Starting restore at 31-JAN-21
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=46 device type=DISK
channel ORA_DISK_1: starting datafile backup set restore
channel ORA_DISK_1: specifying datafile(s) to restore from backup set
channel ORA_DISK_1: restoring datafile 00001 to /u01/app/oracle/oradata/INBAA/system01.dbf
channel ORA_DISK_1: restoring datafile 00002 to /u01/app/oracle/oradata/INBAA/inba_02.dbf
channel ORA_DISK_1: restoring datafile 00003 to /u01/app/oracle/oradata/INBAA/sysaux01.dbf
channel ORA_DISK_1: restoring datafile 00004 to /u01/app/oracle/oradata/INBAA/undotbs01.dbf
channel ORA_DISK_1: restoring datafile 00005 to /u01/app/oracle/oradata/INBAA/inba_01.dbf
channel ORA_DISK_1: restoring datafile 00007 to /u01/app/oracle/oradata/INBAA/users01.dbf
channel ORA_DISK_1: reading from backup piece /u01/app/oracle/recovery_area/INBAA/backupset/2021_01_31/o1_mf_nnndf_TAG20210131T143717_j1dwt60r_.bkp
channel ORA_DISK_1: piece handle=/u01/app/oracle/recovery_area/INBAA/backupset/2021_01_31/o1_mf_nnndf_TAG20210131T143717_j1dwt60r_.bkp tag=TAG20210131T143717
channel ORA_DISK_1: restored backup piece 1
channel ORA_DISK_1: restore complete, elapsed time: 00:00:35
Finished restore at 31-JAN-21
Starting recover at 31-JAN-21
using channel ORA_DISK_1
starting media recovery
archived log for thread 1 with sequence 7 is already on disk as file /u01/app/oracle/recovery_area/INBAA/archivelog/2021_01_31/o1_mf_1_7_j1dww74c_.arc
archived log for thread 1 with sequence 8 is already on disk as file /u01/app/oracle/recovery_area/INBAA/archivelog/2021_01_31/o1_mf_1_8_j1f4jhv9_.arc
archived log for thread 1 with sequence 1 is already on disk as file /u01/app/oracle/recovery_area/INBAA/archivelog/2021_01_31/o1_mf_1_1_j1f6hkwh_.arc
archived log file name=/u01/app/oracle/recovery_area/INBAA/archivelog/2021_01_31/o1_mf_1_7_j1dww74c_.arc thread=1 sequence=7
archived log file name=/u01/app/oracle/recovery_area/INBAA/archivelog/2021_01_31/o1_mf_1_8_j1f4jhv9_.arc thread=1 sequence=8
archived log file name=/u01/app/oracle/recovery_area/INBAA/archivelog/2021_01_31/o1_mf_1_1_j1f6hkwh_.arc thread=1 sequence=1
archived log file name=/u01/app/oracle/recovery_area/INBAA/archivelog/2021_01_31/o1_mf_1_1_j1fcq16s_.arc thread=1 sequence=1
media recovery complete, elapsed time: 00:00:08
Finished recover at 31-JAN-21
RMAN>
Step 11:- Open the database using resetlogs option
Now we open the database with the ALTER DATABASE OPEN RESETLOGS command and see that a new incarnation key (12) has been allocated to the database as the CURRENT incarnation.
SQL> alter database open resetlogs;
Database altered.
RMAN> list incarnation of database;
List of Database Incarnations
DB Key Inc Key DB Name DB ID STATUS Reset SCN Reset Time
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RMAN database point-in-time recovery (DBPITR) restores the database from RMAN backups.
RMAN will be consider all ( required ) backups (full, incremental, transectional) to restore or roll forward to the desire time.
Point in time recovery may be incomplete recovery because it does not use all the available archive logs files or completely recover all changes to your database.
If you want to recover your database to the exact date/time in the past, use RMAN point in time recovery.
Prerequisites :-
Database must be running in archivelog mode.
You must have all the datafile backups available prior to target time to recover.
STEP 1:Check archive log list for the current log sequence number.
SQL> archive log list
Database log mode Archive Mode
Automatic archival Enabled
Archive destination USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence 2
Next log sequence to archive 4
Current log sequence 4
Step 2: Create user for testing and table data for the recovery purpose.
SQL> create user inba identified by inba default tablespace users temporary tablespace temp profile default account unlock;
User created.
SQL> grant connect,resource to inba;
Grant succeeded.
SQL> grant all privileges to inba;
Here you can find the time of log sequence 3 19:19:55 that is the time the data would be available in the database.so we need to go back that time and recover the database using the RMAN backups.
Step 4 : Startup the database at mount stage and connect the rman to recover the database using the log sequence number 3.
Total System Global Area 3019895280 bytes
Fixed Size 8901104 bytes
Variable Size 738197504 bytes
Database Buffers 2264924160 bytes
Redo Buffers 7872512 bytes
Database mounted.
SQL>
[oracle@localhost scripts]$ . ora19c.env
[oracle@localhost scripts]$ rman target /
Recovery Manager: Release 19.0.0.0.0 - Production on Thu Jan 28 19:28:33 2021
Version 19.10.0.0.0
Copyright (c) 1982, 2019, Oracle and/or its affiliates. All rights reserved.
connected to target database: INBAA (DBID=936024966, not open)
RMAN> run
{
set until sequence=3;
restore database;
recover database;
}2> 3> 4> 5> 6>
executing command: SET until clause
Starting restore at 28-JAN-21
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=46 device type=DISK
channel ORA_DISK_1: starting datafile backup set restore
channel ORA_DISK_1: specifying datafile(s) to restore from backup set
channel ORA_DISK_1: restoring datafile 00001 to /u01/app/oracle/oradata/INBAA/system01.dbf
channel ORA_DISK_1: restoring datafile 00003 to /u01/app/oracle/oradata/INBAA/sysaux01.dbf
channel ORA_DISK_1: restoring datafile 00004 to /u01/app/oracle/oradata/INBAA/undotbs01.dbf
channel ORA_DISK_1: restoring datafile 00007 to /u01/app/oracle/oradata/INBAA/users01.dbf
channel ORA_DISK_1: reading from backup piece /u01/app/oracle/recovery_area/INBAA/backupset/2021_01_28/o1_mf_nnndf_TAG20210128T143632_j14znrcx_.bkp
channel ORA_DISK_1: piece handle=/u01/app/oracle/recovery_area/INBAA/backupset/2021_01_28/o1_mf_nnndf_TAG20210128T143632_j14znrcx_.bkp tag=TAG20210128T143632
channel ORA_DISK_1: restored backup piece 1
channel ORA_DISK_1: restore complete, elapsed time: 00:00:56
Finished restore at 28-JAN-21
Starting recover at 28-JAN-21
using channel ORA_DISK_1
starting media recovery
archived log for thread 1 with sequence 9 is already on disk as file /u01/app/oracle/recovery_area/INBAA/archivelog/2021_01_28/o1_mf_1_9_j15g2fl2_.arc
archived log for thread 1 with sequence 1 is already on disk as file /u01/app/oracle/recovery_area/INBAA/archivelog/2021_01_28/o1_mf_1_1_j15j71yb_.arc
archived log for thread 1 with sequence 2 is already on disk as file /u01/app/oracle/recovery_area/INBAA/archivelog/2021_01_28/o1_mf_1_2_j15j83h9_.arc
archived log file name=/u01/app/oracle/recovery_area/INBAA/archivelog/2021_01_28/o1_mf_1_9_j15g2fl2_.arc thread=1 sequence=9
archived log file name=/u01/app/oracle/recovery_area/INBAA/archivelog/2021_01_28/o1_mf_1_1_j15gx9vj_.arc thread=1 sequence=1
archived log file name=/u01/app/oracle/recovery_area/INBAA/archivelog/2021_01_28/o1_mf_1_1_j15j71yb_.arc thread=1 sequence=1
archived log file name=/u01/app/oracle/recovery_area/INBAA/archivelog/2021_01_28/o1_mf_1_2_j15j83h9_.arc thread=1 sequence=2
media recovery complete, elapsed time: 00:00:04
Finished recover at 28-JAN-21
RMAN>
STEP 4: Once the recovery has completed,open the database with resetlogs option and check the data in the table.
SQL> alter database open resetlogs;
Database altered.
SQL>
Step 5:- Check the table data now that the point in time recovery has worked.
SQL> select * from inba.product;
PRO_ID PRO_NAME
11 laptop
12 tv
13 monitor
14 cpu
15 mouse
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