恢复drop掉的pdb flashback

For the purposes of this document, the following fictitious environment is used as an example to describe the procedure:

Pluggable Database Names: PDB1/PDB2/PDB3

************

If flashback of CDB complete, there are chances to previously dropped PDB datafiles goes offline

Reason:
There might be PDB dropped in past and now dropped PDB related datafiles becomes offline during flashback database

SOLUTION

 Situation:
=========

backup of this database taken around scn 4700000

PDB3 was dropped at SCN 4800000

Flashback for CDB was complete until scn 4810629.---这个flashback 有意义吗？ 已经drop掉了啊

Find the files those are offline (those are related to Dropped PDB i.e pdb3)

select file#,name from v$datafile;

For this test, we have two files related to dropped PDB, after flashback was performed both files became offline and file names are UNNAMED00017 & UNNAMED00018

//dbs/UNNAMED00017
//dbs/UNNAMED00018

from alert logfile
=============

Flashback Restore Start
Flashback: Added pluggable database #5: 'PDB3' to the control file.
Flashback: created tablespace #0: 'SYSTEM' of pdb #5 in the controlfile.
Flashback: created OFFLINE file 'UNNAMED00017' for tablespace #0 of pdb #5 in the controlfile.
Filename was:
'//datafile/o1_mf_system_dkl7nplc_.dbf' when dropped.
File will have to be restored from a backup and recovered.
Flashback: created tablespace #1: 'SYSAUX' of pdb #5 in the controlfile.
Flashback: created OFFLINE file 'UNNAMED00018' for tablespace #1 of pdb #5 in the controlfile.
Filename was:
'//datafile/o1_mf_sysaux_dkl7npld_.dbf' when dropped.
File will have to be restored from a backup and recovered.
Flashback: created tablespace #2: 'TEMP' of pdb #5 in the controlfile.
Flashback Restore Complete
Flashback Media Recovery Start

How to recover those files from backup

step 1) restore the datafiles with until scn option

RMAN> run {
set until scn 4810629;
set newname for datafile 17 to '//datafile/datafile171.dbf';
set newname for datafile 18 to '//datafile/datafile181.dbf';
restore pluggable database pdb3;
}

Step 2) switch datafiles to copy (rename the datafiles those where with UNNAMED000xx)

(in this example, datafile 17 and 18 were restored )

RMAN> switch datafile 17 to copy;
RMAN> switch datafile 18 to copy;

you can check the PDBs

SQL> show pdbs

CON_ID CON_NAME OPEN MODE RESTRICTED
---------- ------------------------------ ---------- ----------
2 PDB$SEED READ ONLY NO
3 PDB1 READ WRITE NO
4 PDB2 READ WRITE NO
5 PDB3 MOUNTED

Step 3) Online the datafiles

connect to the pdb and make it online, by default flashback would keep datafiles in offline status

SQL> alter session set container=pdb3;
SQL> alter database datafile '//datafile/datafile171.dbf' online;
SQL> alter database datafile '//datafile/datafile181.dbf' online;

Step 4) recover your PDB files  

  

Below recovery will create auxiliary instance and go for recovery of those datafiles

 

RMAN> run {
set until scn 4810629;
recover pluggable database pdb3;
}

step 5) open the pluggable database in resetlogs

RMAN> alter pluggable database pdb3 open resetlogs