I think I have mentioned few times already that I am not a certified (Certifitted as we call it sarcastically due to the pure ignorance of much of them) DBA, yet I love executing experiments with Oracle database technology and come up with some hacks, tricks etc. As usual, whatever you read ahead is NOT recommended for PRODUCTION environment and if you end up setting up something that works finally for your PRODUCTION instance, well you are sole responsible for it.
For this experiment, we will use one 19c database with multitenant structure installed on Windows 10/11. Before you attempt the below, please make sure that you have taken the backup of control file trace, spfile copy as pfile and a full backup of database using RMAN
Control file backup trace.
SQL>alter database backup controlfile to trace as 'D:\folder_name\control.txt';SPfile to Pfile (This file should be available at $ORACLE_HOME\database\ folder)
SQL>create pfile from spfile;Creating pfile is not mandatory incase if you are restoring the backup to same host and the paths are intact. Pfile becomes useful when you are restoring the database to another host with same directory structure.
Shutdown the database & delete the datafile from paths. For example, my datafiles were in the following paths.
There were three paths from which I needed to delete the data files. From CDB root, PDB seed and PDB itself. You should get a clear idea of the exact locations for your data files from the control file trace export.
Once after deleting the files, start the database at nomount state. The latest version of databases allow you to execute many SQL commands from RMAN itself, however, I always prefer SQL prompt for SQL activities. Suite yourself.
SQL>startup nomountFrom another command/terminal window connect to RMAN
D:\RMAN>rman target /
Recovery Manager: Release 19.0.0.0.0 - Production on Sat Mar 12 11:47:15 2022
Version 19.11.0.0.0
Copyright (c) 1982, 2021, Oracle and/or its affiliates. All rights reserved.
connected to target database: SCTCDB (not mounted)Restore the control file from latest backup
RMAN> restore controlfile from 'D:\RMAN\BKPCONTROL_FILE.CTL_SCTCDB_20220312';
Starting restore at 12-MAR-22
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=498 device type=DISK
channel ORA_DISK_1: restoring control file
channel ORA_DISK_1: restore complete, elapsed time: 00:00:01
output file name=D:\ORACLE19C\DB\ORADATA\SCTCDB\CONTROL01.CTL
output file name=D:\ORACLE19C\DB\ORADATA\SCTCDB\CONTROL02.CTL
Finished restore at 12-MAR-22Now try to mount the database.
RMAN> alter database mount;
released channel: ORA_DISK_1
Statement processedOnce the database mounted, let us see what the schema reprorts
RMAN> report schema;
Populate catalog from the backup.
RMAN> catalog start with 'D:\RMAN';
searching for all files that match the pattern D:\RMAN
List of Files Unknown to the Database
=====================================
File Name: D:\RMAN\BKPCONTROL_FILE.CTL_SCTCDB_20220312
Do you really want to catalog the above files (enter YES or NO)? YES
cataloging files...
cataloging done
List of Cataloged Files
=======================
File Name: D:\RMAN\BKPCONTROL_FILE.CTL_SCTCDB_20220312Once the above completes successfully, we can proceed with restoring the backup.
RMAN> run
2> {allocate channel ch1 device type disk;
3> restore database;
4> switch datafile all;
5> switch tempfile all;
6> release channel ch1;
7> }
allocated channel: ch1
channel ch1: SID=252 device type=DISK
Starting restore at 12-MAR-22
channel ch1: starting datafile backup set restore
channel ch1: specifying datafile(s) to restore from backup set
channel ch1: restoring datafile 00004 to D:\ORACLE19C\DB\ORADATA\SCTCDB\UNDOTBS01.DBF
channel ch1: reading from backup piece D:\RMAN\SCT_SCTCDB_ LVL0_040O6TG6_1_1
channel ch1: piece handle=D:\RMAN\SCT_SCTCDB_ LVL0_040O6TG6_1_1 tag=DAILYFULL_DB_LVL0_BKP
channel ch1: restored backup piece 1
channel ch1: restore complete, elapsed time: 00:00:03
channel ch1: starting datafile backup set restore
channel ch1: specifying datafile(s) to restore from backup set
channel ch1: restoring datafile 00003 to D:\ORACLE19C\DB\ORADATA\SCTCDB\SYSAUX01.DBF
channel ch1: reading from backup piece D:\RMAN\SCT_SCTCDB_ LVL0_020O6TG5_1_1
channel ch1: piece handle=D:\RMAN\SCT_SCTCDB_ LVL0_020O6TG5_1_1 tag=DAILYFULL_DB_LVL0_BKP
channel ch1: restored backup piece 1
channel ch1: restore complete, elapsed time: 00:00:15
channel ch1: starting datafile backup set restore
channel ch1: specifying datafile(s) to restore from backup set
channel ch1: restoring datafile 00005 to D:\ORACLE19C\DB\ORADATA\SCTCDB\PDBSEED\SYSTEM01.DBF
channel ch1: reading from backup piece D:\RMAN\SCT_SCTCDB_ LVL0_050O6TG9_1_1
channel ch1: piece handle=D:\RMAN\SCT_SCTCDB_ LVL0_050O6TG9_1_1 tag=DAILYFULL_DB_LVL0_BKP
channel ch1: restored backup piece 1
channel ch1: restore complete, elapsed time: 00:00:15
channel ch1: starting datafile backup set restore
channel ch1: specifying datafile(s) to restore from backup set
channel ch1: restoring datafile 00009 to D:\ORACLE19C\DB\ORADATA\SCTCDB\SCT\SYSTEM01.DBF
channel ch1: reading from backup piece D:\RMAN\SCT_SCTCDB_ LVL0_030O6TG5_1_1
channel ch1: piece handle=D:\RMAN\SCT_SCTCDB_ LVL0_030O6TG5_1_1 tag=DAILYFULL_DB_LVL0_BKP
channel ch1: restored backup piece 1
channel ch1: restore complete, elapsed time: 00:00:15
channel ch1: starting datafile backup set restore
channel ch1: specifying datafile(s) to restore from backup set
channel ch1: restoring datafile 00011 to D:\ORACLE19C\DB\ORADATA\SCTCDB\SCT\UNDOTBS01.DBF
channel ch1: reading from backup piece D:\RMAN\SCT_SCTCDB_ LVL0_080O6TH9_1_1
channel ch1: piece handle=D:\RMAN\SCT_SCTCDB_ LVL0_080O6TH9_1_1 tag=DAILYFULL_DB_LVL0_BKP
channel ch1: restored backup piece 1
channel ch1: restore complete, elapsed time: 00:00:01
channel ch1: starting datafile backup set restore
channel ch1: specifying datafile(s) to restore from backup set
channel ch1: restoring datafile 00010 to D:\ORACLE19C\DB\ORADATA\SCTCDB\SCT\SYSAUX01.DBF
channel ch1: reading from backup piece D:\RMAN\SCT_SCTCDB_ LVL0_060O6TH2_1_1
channel ch1: piece handle=D:\RMAN\SCT_SCTCDB_ LVL0_060O6TH2_1_1 tag=DAILYFULL_DB_LVL0_BKP
channel ch1: restored backup piece 1
channel ch1: restore complete, elapsed time: 00:00:07
channel ch1: starting datafile backup set restore
channel ch1: specifying datafile(s) to restore from backup set
channel ch1: restoring datafile 00007 to D:\ORACLE19C\DB\ORADATA\SCTCDB\USERS01.DBF
channel ch1: reading from backup piece D:\RMAN\SCT_SCTCDB_ LVL0_0B0O6THG_1_1
channel ch1: piece handle=D:\RMAN\SCT_SCTCDB_ LVL0_0B0O6THG_1_1 tag=DAILYFULL_DB_LVL0_BKP
channel ch1: restored backup piece 1
channel ch1: restore complete, elapsed time: 00:00:01
channel ch1: starting datafile backup set restore
channel ch1: specifying datafile(s) to restore from backup set
channel ch1: restoring datafile 00008 to D:\ORACLE19C\DB\ORADATA\SCTCDB\PDBSEED\UNDOTBS01.DBF
channel ch1: reading from backup piece D:\RMAN\SCT_SCTCDB_ LVL0_090O6THA_1_1
channel ch1: piece handle=D:\RMAN\SCT_SCTCDB_ LVL0_090O6THA_1_1 tag=DAILYFULL_DB_LVL0_BKP
channel ch1: restored backup piece 1
channel ch1: restore complete, elapsed time: 00:00:07
channel ch1: starting datafile backup set restore
channel ch1: specifying datafile(s) to restore from backup set
channel ch1: restoring datafile 00012 to D:\ORACLE19C\DB\ORADATA\SCTCDB\SCT\USERS01.DBF
channel ch1: reading from backup piece D:\RMAN\SCT_SCTCDB_ LVL0_0C0O6THH_1_1
channel ch1: piece handle=D:\RMAN\SCT_SCTCDB_ LVL0_0C0O6THH_1_1 tag=DAILYFULL_DB_LVL0_BKP
channel ch1: restored backup piece 1
channel ch1: restore complete, elapsed time: 00:00:02
channel ch1: starting datafile backup set restore
channel ch1: specifying datafile(s) to restore from backup set
channel ch1: restoring datafile 00006 to D:\ORACLE19C\DB\ORADATA\SCTCDB\PDBSEED\SYSAUX01.DBF
channel ch1: reading from backup piece D:\RMAN\SCT_SCTCDB_ LVL0_070O6TH9_1_1
channel ch1: piece handle=D:\RMAN\SCT_SCTCDB_ LVL0_070O6TH9_1_1 tag=DAILYFULL_DB_LVL0_BKP
channel ch1: restored backup piece 1
channel ch1: restore complete, elapsed time: 00:00:07
channel ch1: starting datafile backup set restore
channel ch1: specifying datafile(s) to restore from backup set
channel ch1: restoring datafile 00001 to D:\ORACLE19C\DB\ORADATA\SCTCDB\SYSTEM01.DBF
channel ch1: reading from backup piece D:\RMAN\SCT_SCTCDB_ LVL0_010O6TG5_1_1
channel ch1: piece handle=D:\RMAN\SCT_SCTCDB_ LVL0_010O6TG5_1_1 tag=DAILYFULL_DB_LVL0_BKP
channel ch1: restored backup piece 1
channel ch1: restore complete, elapsed time: 00:00:35
Finished restore at 12-MAR-22
released channel: ch1With the above restore, I used only one channel, please adjust based on available hardware resources. Once the backup completes, we can recover the database using the available archive logs. For that you need to know what is the latest available sequence number.
RMAN> list backup of archivelog all;
From the image above, you could see that the latest Sequence number for the SCN is 20, however the listing is kind of confusing (remember I am not a DBA, however eventually I will figure out why the listing is messed up). Once the latest sequence number identified, we can try to recover until last sequence + 1
RMAN> run {
2> allocate channel ch1 device type disk;
3> allocate channel ch2 device type disk;
4> allocate channel ch3 device type disk;
5> allocate channel ch4 device type disk;
6> recover database until sequence 21;
7> release channel ch1;
8> release channel ch2;
9> release channel ch3;
10> release channel ch4;
11> }
allocated channel: ch1
channel ch1: SID=252 device type=DISK
allocated channel: ch2
channel ch2: SID=128 device type=DISK
allocated channel: ch3
channel ch3: SID=375 device type=DISK
allocated channel: ch4
channel ch4: SID=499 device type=DISK
Starting recover at 12-MAR-22
starting media recovery
archived log for thread 1 with sequence 19 is already on disk as file D:\ORA\ARCH\SCT0000000019_1096219042_0001.ARC
archived log for thread 1 with sequence 20 is already on disk as file D:\ORA\ARCH\SCT0000000020_1096219042_0001.ARC
archived log file name=D:\ORA\ARCH\SCT0000000019_1096219042_0001.ARC thread=1 sequence=19
archived log file name=D:\ORA\ARCH\SCT0000000020_1096219042_0001.ARC thread=1 sequence=20
media recovery complete, elapsed time: 00:00:01
Finished recover at 12-MAR-22
released channel: ch1
released channel: ch2
released channel: ch3
released channel: ch4Finally, we can open the database resetting online redo log files
RMAN> alter database open resetlogs;Database MUST open without creating any issues at this stage. Continue checking for the database vitals.