RMAN深入解析之--Incarnation應用（不完全恢復）

發布時間：2020-08-13 11:25:22 來源：ITPUB博客閱讀：286 作者：記錄每一次錯誤欄目：關系型數據庫

當在做Media Recover的不完全恢復時，通過resetlogs打開庫，則Incarnation（數據庫對應物）表示這個數據庫的特定的邏輯生存期。當作為DBA可能面臨這樣的還原：需要使用上次執行resetlogs命令打開數據庫前生成的一個備份來進行還原數據庫，或者可能需要還原到執行上一個resetlogs命令之前的時間點。

案例1：（不完全恢復1）

1、table被誤刪除，進行不完全恢復

17:12:11 SYS@ prod>select current_scn from v$database;

CURRENT_SCN

-----------

2123790

17:12:24 SYS@ prod>conn scott/tiger

Connected.

17:12:43 SCOTT@ prod>select count(*) from emp1;

COUNT(*)

----------

Elapsed: 00:00:00.05

17:12:53 SCOTT@ prod>delete from emp1;

28 rows deleted.

Elapsed: 00:00:00.08

17:13:12 SCOTT@ prod>commit;

Commit complete.

Elapsed: 00:00:00.04

17:13:17 SCOTT@ prod>insert into emp1 select * from emp where empno=7788;

1 row created.

Elapsed: 00:00:00.04

17:13:28 SCOTT@ prod>update emp set empno=9999 where empno=7788;

1 row updated.

Elapsed: 00:00:00.03

17:13:43 SCOTT@ prod>commit;

Commit complete.

Elapsed: 00:00:00.04

17:13:45 SCOTT@ prod>select * from emp1;

EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO

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

7788 SCOTT ANALYST 7566 19-APR-87 3000 20

Elapsed: 00:00:00.02

2、執行不完全恢復

RMAN> run {

2> set until scn 2123790;

3> shutdown immediate;

4> startup mount;

5> restore database;

6> recover database;

7> alter database open resetlogs;

8> sql'alter system switch logfile';

9> }

executing command: SET until clause

using target database control file instead of recovery catalog

database closed

database dismounted

Oracle instance shut down

connected to target database (not started)

Oracle instance started

database mounted

Total System Global Area 835104768 bytes

Fixed Size 2217952 bytes

Variable Size 775948320 bytes

Database Buffers 54525952 bytes

Redo Buffers 2412544 bytes

Starting restore at 15-JUL-14

allocated channel: ORA_DISK_1

channel ORA_DISK_1: SID=18 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/prod/system01.dbf

channel ORA_DISK_1: restoring datafile 00002 to /u01/app/oracle/oradata/prod/sysaux01.dbf

channel ORA_DISK_1: restoring datafile 00003 to /u01/app/oracle/oradata/prod/undotbs1.dbf

channel ORA_DISK_1: restoring datafile 00004 to /u01/app/oracle/oradata/prod/users01.dbf

channel ORA_DISK_1: restoring datafile 00005 to /u01/app/oracle/oradata/prod/example01.dbf

channel ORA_DISK_1: restoring datafile 00006 to /u01/app/oracle/oradata/prod/tbs1.dbf

channel ORA_DISK_1: restoring datafile 00007 to /u01/app/oracle/oradata/prod/undotbs2.dbf

channel ORA_DISK_1: restoring datafile 00008 to /u01/app/oracle/oradata/prod/perftbs01.dbf

channel ORA_DISK_1: reading from backup piece /u01/app/oracle/product/11.2.0/db_1/dbs/0lpcfu61_1_1

channel ORA_DISK_1: piece handle=/u01/app/oracle/product/11.2.0/db_1/dbs/0lpcfu61_1_1 tag=TAG20140703T171545

channel ORA_DISK_1: restored backup piece 1

channel ORA_DISK_1: restore complete, elapsed time: 00:01:16

Finished restore at 15-JUL-14

Starting recover at 15-JUL-14

using channel ORA_DISK_1

starting media recovery

archived log for thread 1 with sequence 17 is already on disk as file /dsk4/arch2/arch_1_17_851265252.log

archived log for thread 1 with sequence 18 is already on disk as file /dsk4/arch2/arch_1_18_851265252.log

archived log for thread 1 with sequence 19 is already on disk as file /dsk4/arch2/arch_1_19_851265252.log

archived log file name=/dsk4/arch2/arch_1_17_851265252.log thread=1 sequence=17

media recovery complete, elapsed time: 00:00:09

Finished recover at 15-JUL-14

database opened

3、驗證

[oracle@rh7 ~]$ sqlplus '/as sysdba'

SQL*Plus: Release 11.2.0.1.0 Production on Tue Jul 15 17:26:10 2014

Connected to:

Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production

With the Partitioning, OLAP, Data Mining and Real Application Testing options

17:26:10 SYS@ prod>select count(*) from scott.emp1;

COUNT(*)

----------

Elapsed: 00:00:00.03

17:27:09 SYS@ prod>

數據被恢復！

5、查看Incarnation

RMAN> list incarnation;

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

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

1 1 PROD 239333010 PARENT 1 15-AUG-09

2 2 PROD 239333010 PARENT 945184 30-SEP-13

3 3 PROD 239333010 PARENT 1087512 18-MAY-14

4 4 PROD 239333010 PARENT 1857377 26-JUN-14

5 5 PROD 239333010 CURRENT 2123791 15-JUL-14

RMAN>

RMAN> list backup of database;

List of Backup Sets

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

BS Key Type LV Size Device Type Elapsed Time Completion Time

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

17 Full 1.13G DISK 00:01:21 03-JUL-14

BP Key: 17 Status: AVAILABLE Compressed: NO Tag: TAG20140703T171545

Piece Name: /u01/app/oracle/product/11.2.0/db_1/dbs/0lpcfu61_1_1

List of Datafiles in backup set 17

File LV Type Ckp SCN Ckp Time Name

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

1 Full 2066885 03-JUL-14 /u01/app/oracle/oradata/prod/system01.dbf

2 Full 2066885 03-JUL-14 /u01/app/oracle/oradata/prod/sysaux01.dbf

3 Full 2066885 03-JUL-14 /u01/app/oracle/oradata/prod/undotbs1.dbf

4 Full 2066885 03-JUL-14 /u01/app/oracle/oradata/prod/users01.dbf

5 Full 2066885 03-JUL-14 /u01/app/oracle/oradata/prod/example01.dbf

6 Full 2066885 03-JUL-14 /u01/app/oracle/oradata/prod/tbs1.dbf

7 Full 2066885 03-JUL-14 /u01/app/oracle/oradata/prod/undotbs2.dbf

8 Full 2066885 03-JUL-14 /u01/app/oracle/oradata/prod/perftbs01.dbf

案例2：（不完全恢復2）

1、table被誤刪除，通過不完全恢復進行恢復

17:42:24 SYS@ prod>conn scott/tiger

Connected.

17:42:28 SCOTT@ prod>insert into emp1 select * from emp where rownum <4;

3 rows created.

Elapsed: 00:00:00.05

17:42:42 SCOTT@ prod>commit;

Commit complete.

Elapsed: 00:00:00.01

17:42:44 SCOTT@ prod>insert into emp1 select * from emp where rownum <5;

4 rows created.

Elapsed: 00:00:00.02

17:42:52 SCOTT@ prod>commit;

Commit complete.

Elapsed: 00:00:00.05

17:42:55 SCOTT@ prod>conn /as sysdba

Connected.

17:43:01 SYS@ prod>select current_scn from v$database;

CURRENT_SCN

-----------

2124840

17:43:13 SYS@ prod>alter system switch logfile;

System altered.

Elapsed: 00:00:00.10

17:43:38 SYS@ prod>conn scott/tiger

Connected.

17:43:42 SCOTT@ prod>select count(*) from scott.emp1;

COUNT(*)

----------

Elapsed: 00:00:00.02

17:43:48 SCOTT@ prod>delete from emp1;

35 rows deleted.

Elapsed: 00:00:00.04

17:43:56 SCOTT@ prod>commit;

Commit complete.

Elapsed: 00:00:00.01

17:43:58 SCOTT@ prod>insert into emp1 select * from emp where empno=7788;

1 row created.

Elapsed: 00:00:00.01

17:44:09 SCOTT@ prod>update emp1 set empno=8888;

1 row updated.

Elapsed: 00:00:00.01

17:44:16 SCOTT@ prod>commit;

Commit complete.

Elapsed: 00:00:00.02

17:44:17 SCOTT@ prod>select * from emp1;

EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO

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

8888 SCOTT ANALYST 7566 19-APR-87 3000 20

Elapsed: 00:00:00.03

2、通過rman做不完全恢復

RMAN> run {

set until scn 2124840;

2> shutdown immediate;

3> 4> startup mount;