【12C考题精解】OCP 1z0-060 QUESTION 8: Recovery of a Tablespace in the CDB

QUESTION 8

Your multitenant container (CDB) containing three pluggable databases (PDBs) is running in ARCHIVELOG mode. You find that the SYSAUX tablespace is corrupted in the root container. The steps to recover the tablespace are as follows:
   1. Mount the CDB.
   2. Close all the PDBs.
   3. Open the database.
   4. Apply the archive redo logs.
   5. Restore the data file.
   6. Take the SYSAUX tablespace offline.
   7. Place the SYSAUX tablespace online.
   8. Open all the PDBs with RESETLOGS.
   9. Open the database with RESETLOGS.
   10. Execute the command SHUTDOWN ABORT.
Which option identifies the correct sequence to recover the SYSAUX tablespace?

A. 6,5,4,7
B. 10,1,2,5,8
C. 10,1,2,5,4,9,8
D. 10,1,5,8,10

【题目示意】
本题考察的是CDB中的SYSAUX表空间完全恢复。

【解析】
在数据库已经open的情况下，某些非关键数据文件发生损坏。只需要在保证数据库其他数据文件可用的状态下，对损坏的文件或损坏文件所在的表空间进行restore和recover操作。不需要关闭数据库，再进行恢复。在restore之前，要求表空间处于offline状态。

【实验】
1.修改数据库为归档模式

[oracle@dbstyle ~]$ sqlplus / as sysdba

SQL*Plus: Release 12.1.0.1.0 Production on Mon Aug 11 14:58:41 2014

Copyright (c) 1982, 2013, Oracle.  All rights reserved.

Connected to an idle instance.

SYS@DBSTYLE> startup
ORACLE instance started.

Total System Global Area 2121183232 bytes
Fixed Size          2290360 bytes
Variable Size        1308626248 bytes
Database Buffers      805306368 bytes
Redo Buffers            4960256 bytes
Database mounted.
Database opened.
SYS@DBSTYLE> shu immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SYS@DBSTYLE> startup mount
ORACLE instance started.

Total System Global Area 2121183232 bytes
Fixed Size                 2290360 bytes
Variable Size        1308626248 bytes
Database Buffers             805306368 bytes
Redo Buffers            4960256 bytes
Database mounted.
SYS@DBSTYLE> alter database archivelog;

Database altered.

SYS@DBSTYLE> alter database open;

Database altered.

SYS@DBSTYLE> alter system switch logfile;

System altered.

2.使用RMAN备份数据库

SYS@DBSTYLE> !rman

Recovery Manager: Release 12.1.0.1.0 - Production on Mon Aug 11 15:00:13 2014

Copyright (c) 1982, 2013, Oracle and/or its affiliates.  All rights reserved.

RMAN> connect target /

connected to target database: DBSTYLE (DBID=2767578829)

RMAN> backup database;

Starting backup at 11-AUG-14
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=50 device type=DISK
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/DBSTYLE/undotbs01.dbf
input datafile file number=00001 name=/u01/app/oracle/oradata/DBSTYLE/system01.dbf
input datafile file number=00003 name=/u01/app/oracle/oradata/DBSTYLE/sysaux01.dbf
input datafile file number=00006 name=/u01/app/oracle/oradata/DBSTYLE/users01.dbf
channel ORA_DISK_1: starting piece 1 at 11-AUG-14
channel ORA_DISK_1: finished piece 1 at 11-AUG-14
piece handle=/u01/app/oracle/fast_recovery_area/DBSTYLE/backupset/2014_08_11/o1_mf_nnndf_TAG20140811T150021_9yjtj5z5_.bkp tag=TAG20140811T150021 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:26
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
input datafile file number=00008 name=/u01/app/oracle/oradata/DBSTYLE/DBS/sysaux01.dbf
input datafile file number=00007 name=/u01/app/oracle/oradata/DBSTYLE/DBS/system01.dbf
input datafile file number=00009 name=/u01/app/oracle/oradata/DBSTYLE/DBS/DBS_users01.dbf
channel ORA_DISK_1: starting piece 1 at 11-AUG-14
channel ORA_DISK_1: finished piece 1 at 11-AUG-14
piece handle=/u01/app/oracle/fast_recovery_area/DBSTYLE/FDD32A078F321802E0430A50A8C0F4FF/backupset/2014_08_11/o1_mf_nnndf_TAG20140811T150021_9yjtjz65_.bkp tag=TAG20140811T150021 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:07
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
input datafile file number=00004 name=/u01/app/oracle/oradata/DBSTYLE/pdbseed/sysaux01.dbf
input datafile file number=00002 name=/u01/app/oracle/oradata/DBSTYLE/pdbseed/system01.dbf
channel ORA_DISK_1: starting piece 1 at 11-AUG-14
channel ORA_DISK_1: finished piece 1 at 11-AUG-14
piece handle=/u01/app/oracle/fast_recovery_area/DBSTYLE/FDD22BF463BC0F53E0430A50A8C0EDD2/backupset/2014_08_11/o1_mf_nnndf_TAG20140811T150021_9yjtk68h_.bkp tag=TAG20140811T150021 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:07
Finished backup at 11-AUG-14

Starting Control File and SPFILE Autobackup at 11-AUG-14
piece handle=/u01/app/oracle/fast_recovery_area/DBSTYLE/autobackup/2014_08_11/o1_mf_s_855327661_9yjtkff8_.bkp comment=NONE
Finished Control File and SPFILE Autobackup at 11-AUG-14

RMAN> list backup;


List of Backup Sets
===================


BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ ---------------
1       Full    2.09G      DISK        00:00:16     11-AUG-14      
        BP Key: 1   Status: AVAILABLE  Compressed: NO  Tag: TAG20140811T150021
        Piece Name: /u01/app/oracle/fast_recovery_area/DBSTYLE/backupset/2014_08_11/o1_mf_nnndf_TAG20140811T150021_9yjtj5z5_.bkp
  List of Datafiles in backup set 1
  File LV Type Ckp SCN    Ckp Time  Name
  ---- -- ---- ---------- --------- ----
  1       Full 1564193    11-AUG-14 /u01/app/oracle/oradata/DBSTYLE/system01.dbf
  3       Full 1564193    11-AUG-14 /u01/app/oracle/oradata/DBSTYLE/sysaux01.dbf
  5       Full 1564193    11-AUG-14 /u01/app/oracle/oradata/DBSTYLE/undotbs01.dbf
  6       Full 1564193    11-AUG-14 /u01/app/oracle/oradata/DBSTYLE/users01.dbf

BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ ---------------
2       Full    762.73M    DISK        00:00:04     11-AUG-14      
        BP Key: 2   Status: AVAILABLE  Compressed: NO  Tag: TAG20140811T150021
        Piece Name: /u01/app/oracle/fast_recovery_area/DBSTYLE/FDD32A078F321802E0430A50A8C0F4FF/backupset/2014_08_11/o1_mf_nnndf_TAG20140811T150021_9yjtjz65_.bkp
  List of Datafiles in backup set 2
  Container ID: 3, PDB Name: DBS
  File LV Type Ckp SCN    Ckp Time  Name
  ---- -- ---- ---------- --------- ----
  7       Full 1563088    11-AUG-14 /u01/app/oracle/oradata/DBSTYLE/DBS/system01.dbf
  8       Full 1563088    11-AUG-14 /u01/app/oracle/oradata/DBSTYLE/DBS/sysaux01.dbf
  9       Full 1563088    11-AUG-14 /u01/app/oracle/oradata/DBSTYLE/DBS/DBS_users01.dbf

BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ ---------------
3       Full    761.49M    DISK        00:00:04     11-AUG-14      
        BP Key: 3   Status: AVAILABLE  Compressed: NO  Tag: TAG20140811T150021
        Piece Name: /u01/app/oracle/fast_recovery_area/DBSTYLE/FDD22BF463BC0F53E0430A50A8C0EDD2/backupset/2014_08_11/o1_mf_nnndf_TAG20140811T150021_9yjtk68h_.bkp
  List of Datafiles in backup set 3
  Container ID: 2, PDB Name: PDB$SEED
  File LV Type Ckp SCN    Ckp Time  Name
  ---- -- ---- ---------- --------- ----
  2       Full 1539785    10-JUL-14 /u01/app/oracle/oradata/DBSTYLE/pdbseed/system01.dbf
  4       Full 1539785    10-JUL-14 /u01/app/oracle/oradata/DBSTYLE/pdbseed/sysaux01.dbf

BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ ---------------
4       Full    17.20M     DISK        00:00:00     11-AUG-14      
        BP Key: 4   Status: AVAILABLE  Compressed: NO  Tag: TAG20140811T150101
        Piece Name: /u01/app/oracle/fast_recovery_area/DBSTYLE/autobackup/2014_08_11/o1_mf_s_855327661_9yjtkff8_.bkp
  SPFILE Included: Modification time: 11-AUG-14
  SPFILE db_unique_name: DBSTYLE
  Control File Included: Ckp SCN: 1565204      Ckp time: 11-AUG-14

3.删除sysaux01.dbf数据文件，模拟sysaux表空间损坏

[oracle@dbstyle DBSTYLE]$ rm -f sysaux01.dbf

4.使用RMAN进行restore操作，此时由于表空间没有离线，因此无法进行restore

RMAN> restore tablespace sysaux;

Starting restore at 11-AUG-14
using channel ORA_DISK_1

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 00003 to /u01/app/oracle/oradata/DBSTYLE/sysaux01.dbf
channel ORA_DISK_1: reading from backup piece /u01/app/oracle/fast_recovery_area/DBSTYLE/backupset/2014_08_11/o1_mf_nnndf_TAG20140811T150021_9yjtj5z5_.bkp
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of restore command at 08/11/2014 15:18:45
ORA-19870: error while restoring backup piece /u01/app/oracle/fast_recovery_area/DBSTYLE/backupset/2014_08_11/o1_mf_nnndf_TAG20140811T150021_9yjtj5z5_.bkp
ORA-19573: cannot obtain exclusive enqueue for datafile 3

5.将SYSAUX表空间离线，此时需要使用offline immediate命令

[oracle@dbstyle ~]$ sqlplus / as sysdba

SQL*Plus: Release 12.1.0.1.0 Production on Mon Aug 11 15:01:27 2014

Copyright (c) 1982, 2013, Oracle.  All rights reserved.


Connected to:
Oracle Database 12c Enterprise Edition Release 12.1.0.1.0 - 64bit Production
With the Partitioning, Oracle Label Security, OLAP, Advanced Analytics
and Real Application Testing options

SYS@DBSTYLE> alter tablespace sysaux offline;
alter tablespace sysaux offline
*
ERROR at line 1:
ORA-01116: error in opening database file 3
ORA-01110: data file 3: '/u01/app/oracle/oradata/DBSTYLE/sysaux01.dbf'
ORA-27041: unable to open file
Linux-x86_64 Error: 2: No such file or directory
Additional information: 3

SYS@DBSTYLE> alter tablespace sysaux offline immediate;

Tablespace altered.

SYS@DBSTYLE> select tablespace_name,status from dba_tablespaces;

TABLESPACE_NAME            STATUS
------------------------------ ---------
SYSTEM                 ONLINE
SYSAUX                 OFFLINE
UNDOTBS1               ONLINE
TEMP                   ONLINE
USERS                  ONLINE

6.再次使用RMAN恢复表空间

RMAN> restore tablespace sysaux;

Starting restore at 11-AUG-14
using channel ORA_DISK_1

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 00003 to /u01/app/oracle/oradata/DBSTYLE/sysaux01.dbf
channel ORA_DISK_1: reading from backup piece /u01/app/oracle/fast_recovery_area/DBSTYLE/backupset/2014_08_11/o1_mf_nnndf_TAG20140811T150021_9yjtj5z5_.bkp
channel ORA_DISK_1: piece handle=/u01/app/oracle/fast_recovery_area/DBSTYLE/backupset/2014_08_11/o1_mf_nnndf_TAG20140811T150021_9yjtj5z5_.bkp tag=TAG20140811T150021
channel ORA_DISK_1: restored backup piece 1
channel ORA_DISK_1: restore complete, elapsed time: 00:00:07
Finished restore at 11-AUG-14

RMAN> recover tablespace sysaux;

Starting recover at 11-AUG-14
using channel ORA_DISK_1

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

Finished recover at 11-AUG-14

RMAN> alter tablespace sysaux online;

Statement processed

RMAN>

7.SYSAUX表空间恢复正常

SYS@DBSTYLE> select tablespace_name,status from dba_tablespaces;

TABLESPACE_NAME            STATUS
------------------------------ ---------
SYSTEM                 ONLINE
SYSAUX                 ONLINE
UNDOTBS1               ONLINE
TEMP                   ONLINE
USERS                  ONLINE

SYS@DBSTYLE>

【小结】
无论CDB或者PDB，如果是非关键表空间发生损坏，对数据库影响最小的处理方法就是，让损坏的表空间离线，然后进行restore和recovery，进而使表空间恢复正常。因此A选项最合理。

【答案】 A

相关参考
http://docs.oracle.com/database/121/BRADV/rcmcomre.htm#BRADV89773

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