OCP-1Z0-052-V8.02-80题

80. You perform differential incremental level 1 backups of your database on each working day and level 0

backup on Sundays, to tape. 

Which two statements are true about differential incremental backups? (Choose two.)

A.The backup performed on Sundays contains all the blocks that have ever been used in the database.

B.The backup performed on Sundays contains all the blocks that have changed since the last level 1

backup.

C.The backup performed on each working day contains all the blocks that have changed since the last

level 0 backup.

D.The backup performed on Monday contains all the blocks that have changed since the level 0 backup,

and every other working day contains all the blocks that have changed since the level 1 backup.

Answer: AD  

 

题目备份策略如下：

 

执行增量备份操作时，首先需要的是增量基本备份(incremental base backup),即level 0，今后所有的增量备份都是基于这个基本备份的。

每次执行数据库的备份操作时，都可以通过backup命令incremental参数来为备份派一个增量级别标识符。

基本备份的增量级别为0，并且必须有基本备份才能够执行其它类型的增量备份操作。

如果没有生成基本备份就尝试执行增量备份操作（这个增量备份操作使用0以外的备份级别），RMAN就自动执行基本备份操作。

下面是一个执行基本增量备份操作的命令：

 

 

1、首先使用rman连接目标库。 rman target /

 

[oracle@rtest ~]$ rman target /

 

Recovery Manager: Release 11.2.0.3.0 - Production on Tue Sep 17 10:12:39 2013

 

Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.

 

connected to target database: TEST0910 (DBID=1912424611)

 

 

2、执行0级增量备份。                   backup incremental level 0 database

 

RMAN> backup incremental level 0 database;

 

 

Starting backup at 17-SEP-13

using channel ORA_DISK_1

channel ORA_DISK_1: starting incremental level 0 datafile backup set

channel ORA_DISK_1: specifying datafile(s) in backup set

input datafile file number=00001 name=/u01/app/oracle/oradata/test0910/system01.dbf

input datafile file number=00002 name=/u01/app/oracle/oradata/test0910/sysaux01.dbf

input datafile file number=00005 name=/u01/app/oracle/oradata/test0910/example01.dbf

input datafile file number=00003 name=/u01/app/oracle/oradata/test0910/undotbs01.dbf

input datafile file number=00006 name=/u01/app/oracle/oradata/test0910/testtb.dbf

input datafile file number=00004 name=/u01/app/oracle/oradata/test0910/users01.dbf

channel ORA_DISK_1: starting piece 1 at 17-SEP-13

channel ORA_DISK_1: finished piece 1 at 17-SEP-13

piece handle=/u01/app/oracle/fast_recovery_area/TEST0910/backupset/2013_09_17/o1_mf_nnnd0_TAG20130917T101737_93js455s_.bkp tag=TAG20130917T101737comment=NONE

channel ORA_DISK_1: backup set complete, elapsed time: 00:17:20

channel ORA_DISK_1: starting incremental level 0 datafile backup set

channel ORA_DISK_1: specifying datafile(s) in backup set

including current control file in backup set

including current SPFILE in backup set

channel ORA_DISK_1: starting piece 1 at 17-SEP-13

channel ORA_DISK_1: finished piece 1 at 17-SEP-13

piece handle=/u01/app/oracle/fast_recovery_area/TEST0910/backupset/2013_09_17/o1_mf_ncsn0_TAG20130917T101737_93jt4oct_.bkp tag=TAG20130917T101737 comment=NONE

channel ORA_DISK_1: backup set complete, elapsed time: 00:00:08

Finished backup at 17-SEP-13

 

 

3、执行1级增量备份。          backup incremental level 1 database;

 

RMAN> backup incremental level 1 database;

 

Starting backup at 17-SEP-13

using channel ORA_DISK_1

channel ORA_DISK_1: starting incremental level 1 datafile backup set

channel ORA_DISK_1: specifying datafile(s) in backup set

input datafile file number=00001 name=/u01/app/oracle/oradata/test0910/system01.dbf

input datafile file number=00002 name=/u01/app/oracle/oradata/test0910/sysaux01.dbf

input datafile file number=00005 name=/u01/app/oracle/oradata/test0910/example01.dbf

input datafile file number=00003 name=/u01/app/oracle/oradata/test0910/undotbs01.dbf

input datafile file number=00006 name=/u01/app/oracle/oradata/test0910/testtb.dbf

input datafile file number=00004 name=/u01/app/oracle/oradata/test0910/users01.dbf

channel ORA_DISK_1: starting piece 1 at 17-SEP-13

channel ORA_DISK_1: finished piece 1 at 17-SEP-13

piece handle=/u01/app/oracle/fast_recovery_area/TEST0910/backupset/2013_09_17/o1_mf_nnnd1_TAG20130917T103557_93jt6hjt_.bkp tag=TAG20130917T103557 comment=NONE

channel ORA_DISK_1: backup set complete, elapsed time: 00:01:55

channel ORA_DISK_1: starting incremental level 1 datafile backup set

channel ORA_DISK_1: specifying datafile(s) in backup set

including current control file in backup set

including current SPFILE in backup set

channel ORA_DISK_1: starting piece 1 at 17-SEP-13

channel ORA_DISK_1: finished piece 1 at 17-SEP-13

piece handle=/u01/app/oracle/fast_recovery_area/TEST0910/backupset/2013_09_17/o1_mf_ncsn1_TAG20130917T103557_93jtb225_.bkp tag=TAG20130917T103557 comment=NONE

channel ORA_DISK_1: backup set complete, elapsed time: 00:00:08

Finished backup at 17-SEP-13

 

 

查看备份集：

RMAN> list backup;

 

 

List of Backup Sets

===================

 

BS Key  Type LV Size       Device Type Elapsed Time Completion Time

------- ---- -- ---------- ----------- ------------ ---------------

6       Incr 0  1.16G      DISK        00:17:14     17-SEP-13     

        BP Key: 6   Status: AVAILABLE  Compressed: NO  Tag: TAG20130917T101737

        Piece Name: /u01/app/oracle/fast_recovery_area/TEST0910/backupset/2013_09_17/o1_mf_nnnd0_TAG20130917T101737_93js455s_.bkp

  List of Datafiles in backup set 6

  File LV Type Ckp SCN    Ckp Time  Name

  ---- -- ---- ---------- --------- ----

  1    0  Incr 1506893    17-SEP-13 /u01/app/oracle/oradata/test0910/system01.dbf

  2    0  Incr 1506893    17-SEP-13 /u01/app/oracle/oradata/test0910/sysaux01.dbf

  3    0  Incr 1506893    17-SEP-13 /u01/app/oracle/oradata/test0910/undotbs01.dbf

  4    0  Incr 1506893    17-SEP-13 /u01/app/oracle/oradata/test0910/users01.dbf

  5    0  Incr 1506893    17-SEP-13 /u01/app/oracle/oradata/test0910/example01.dbf

  6    0  Incr 1506893    17-SEP-13 /u01/app/oracle/oradata/test0910/testtb.dbf

 

BS Key  Type LV Size       Device Type Elapsed Time Completion Time

------- ---- -- ---------- ----------- ------------ ---------------

7       Incr 0  9.36M      DISK        00:00:08     17-SEP-13     

        BP Key: 7   Status: AVAILABLE  Compressed: NO  Tag: TAG20130917T101737

        Piece Name: /u01/app/oracle/fast_recovery_area/TEST0910/backupset/2013_09_17/o1_mf_ncsn0_TAG20130917T101737_93jt4oct_.bkp

  SPFILE Included: Modification time: 16-SEP-13

  SPFILE db_unique_name: TEST0910

  Control File Included: Ckp SCN: 1507287      Ckp time: 17-SEP-13

 

BS Key  Type LV Size       Device Type Elapsed Time Completion Time

------- ---- -- ---------- ----------- ------------ ---------------

8       Incr 1  392.00K    DISK        00:01:55     17-SEP-13     

        BP Key: 8   Status: AVAILABLE  Compressed: NO  Tag: TAG20130917T103557

        Piece Name: /u01/app/oracle/fast_recovery_area/TEST0910/backupset/2013_09_17/o1_mf_nnnd1_TAG20130917T103557_93jt6hjt_.bkp

  List of Datafiles in backup set 8

  File LV Type Ckp SCN    Ckp Time  Name

  ---- -- ---- ---------- --------- ----

  1    1  Incr 1507334    17-SEP-13 /u01/app/oracle/oradata/test0910/system01.dbf

  2    1  Incr 1507334    17-SEP-13 /u01/app/oracle/oradata/test0910/sysaux01.dbf

  3    1  Incr 1507334    17-SEP-13 /u01/app/oracle/oradata/test0910/undotbs01.dbf

  4    1  Incr 1507334    17-SEP-13 /u01/app/oracle/oradata/test0910/users01.dbf

  5    1  Incr 1507334    17-SEP-13 /u01/app/oracle/oradata/test0910/example01.dbf

  6    1  Incr 1507334    17-SEP-13 /u01/app/oracle/oradata/test0910/testtb.dbf

 

BS Key  Type LV Size       Device Type Elapsed Time Completion Time

------- ---- -- ---------- ----------- ------------ ---------------

9       Incr 1  9.36M      DISK        00:00:04     17-SEP-13     

        BP Key: 9   Status: AVAILABLE  Compressed: NO  Tag: TAG20130917T103557

        Piece Name: /u01/app/oracle/fast_recovery_area/TEST0910/backupset/2013_09_17/o1_mf_ncsn1_TAG20130917T103557_93jtb225_.bkp

  SPFILE Included: Modification time: 16-SEP-13

  SPFILE db_unique_name: TEST0910

  Control File Included: Ckp SCN: 1507384      Ckp time: 17-SEP-13

 

 

其实增量备份分为差异备份和累积备份，这是两种执行增量备份操作的不同方法。

这道题目是讲差异增量备份。

差异备份是RMAN生成的增量备份的默认类型。对于差异备份来说，RMAN会备份自上一次同级或低级差异增量备份以来所有发生变化的数据块。

 

如图：本题是说星期天进行级别为０的差异增量备份操作，这个备份会操作备份整个数据库。

根据这个级别为0的备份，我们在星期一到星期六进行级别为1的差异增量备份操作。

使用差异备份，每天的备份将包含自一次差异备份以来发生的所有更改。

最后，在下一个星期天，进行别一次基本备份（即级别为０的增量备份）。

 

Sunday

An incremental level 0 backup backs up all blocks that have ever been in use in this database.

0级增量备份会备份所有曾经在此数据库中使用的块。

Monday through Saturday

On each day from Monday through Saturday, a differential incremental level 1 backup backs up all blocks that have changed since the most recent incremental backup at level 1 or 0. The Monday backup copies blocks changed since Sunday level 0 backup, the Tuesday backup copies blocks changed since the Monday level 1 backup, and so forth.

从星期一到星期六的每一天，1级增量备份备份最近1或0级增量备份以来所有更改过的块。周一备份周日0级备份以来变化的块，周二备份周一1级备份改变的块，等等。

 

官网参考：http://docs.oracle.com/cd/E11882_01/backup.112/e10642/rcmcncpt.htm#sthref707