当在做Media Recover的不完全恢复时，通过resetlogs打开库，则Incarnation（数据库对应物）表示这个数据库的特定的逻辑生存期。当作为DBA可能面临这样的还原：需要使用上次执行resetlogs命令打开数据库前生成的一个备份来进行还原数据库，或者可能需要还原到执行上一个resetlogs命令之前的时间点。
案例1：（不完全恢复1）
1、table被误删除，进行不完全恢复
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(*)
----------
28
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、执行不完全恢复
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、验证
[oracle@rh7 ~]$ sqlplus '/as sysdba'
SQL*Plus: Release 11.2.0.1.0 Production on Tue Jul 15 17:26:10 2014
Copyright (c) 1982, 2009, Oracle. All rights reserved.
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(*)
----------
28
Elapsed: 00:00:00.03
17:27:09 SYS@ prod>
数据被恢复！
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：（不完全恢复2）
1、table被误删除，通过不完全恢复进行恢复
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(*)
----------
35
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、通过rman做不完全恢复
RMAN> run {
set until scn 2124840;
2> shutdown immediate;
3> 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
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: 00:01:25
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 for thread 1 with sequence 20 is already on disk as file /dsk4/arch2/arch_1_20_851265252.log
archived log for thread 1 with sequence 1 is already on disk as file /dsk4/arch2/arch_1_1_853003284.log
archived log file name=/dsk4/arch2/arch_1_17_851265252.log thread=1 sequence=17
archived log file name=/dsk4/arch2/arch_1_18_851265252.log thread=1 sequence=18
archived log file name=/dsk4/arch2/arch_1_19_851265252.log thread=1 sequence=19
archived log file name=/dsk4/arch2/arch_1_20_851265252.log thread=1 sequence=20
media recovery complete, elapsed time: 00:00:10
Finished recover at 15-JUL-14
database opened
3、验证
[oracle@rh7 ~]$ sqlplus '/as sysdba'
SQL*Plus: Release 11.2.0.1.0 Production on Tue Jul 15 17:48:52 2014
Copyright (c) 1982, 2009, Oracle. All rights reserved.
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
17:48:52 SYS@ prod>select count(*) from scott.emp1;
COUNT(*)
----------
35
Elapsed: 00:00:00.03
数据恢复成功！
4、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 PARENT 2123791 15-JUL-14
6 6 PROD 239333010 CURRENT 2124841 15-JUL-14
注意：2124841 为当前Incarnation ！
案例3：（不完全恢复3）
1、将数据库再次恢复到当前Incarnation前
RMAN> run {
set until scn 2122840;
3> shutdown immediate;
4> startup mount;
5> restore database;
6> recover database;
7> alter database open resetlogs;
8> }
executing command: SET until clause
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of shutdown command at 07/15/2014 17:51:17
RMAN-20208: UNTIL CHANGE is before RESETLOGS change
---恢复出错，不能再恢复到当前Incarnation前 ！
2、查看Incarnation
RMAN> list incarnation;
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 PARENT 2123791 15-JUL-14
6 6 PROD 239333010 CURRENT 2124841 15-JUL-14
3、重新执行恢复
1、关闭数据库
RMAN> shutdown immediate;
database closed
database dismounted
Oracle instance shut down
2、启动数据库到nomount
RMAN> startup mount;
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
3、恢复Incarnation到前一个
RMAN> reset database to incarnation 5;
database reset to incarnation 5
RMAN> list incarnation;
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
6 6 PROD 239333010 ORPHAN 2124841 15-JUL-14
4、restore数据库
RMAN> restore database until scn 2124835;
Starting restore at 15-JUL-14
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=21 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: 00:01:15
Finished restore at 15-JUL-14
5、Recover 数据库
RMAN> recover database until scn 2124835;
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 for thread 1 with sequence 20 is already on disk as file /dsk4/arch2/arch_1_20_851265252.log
archived log for thread 1 with sequence 1 is already on disk as file /dsk4/arch2/arch_1_1_853003284.log
archived log file name=/dsk4/arch2/arch_1_17_851265252.log thread=1 sequence=17
archived log file name=/dsk4/arch2/arch_1_18_851265252.log thread=1 sequence=18
archived log file name=/dsk4/arch2/arch_1_19_851265252.log thread=1 sequence=19
archived log file name=/dsk4/arch2/arch_1_20_851265252.log thread=1 sequence=20
archived log file name=/dsk4/arch2/arch_1_1_853003284.log thread=1 sequence=1
media recovery complete, elapsed time: 00:00:08
Finished recover at 15-JUL-14
6、查看Incarnation
RMAN> list incarnation;
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
6 6 PROD 239333010 ORPHAN 2124841 15-JUL-14
7、打开数据库（resetlogs）
RMAN> alter database open resetlogs;
database opened
RMAN> list incarnation;
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 PARENT 2123791 15-JUL-14
7 7 PROD 239333010 CURRENT 2124836 15-JUL-14
6 6 PROD 239333010 ORPHAN 2124841 15-JUL-14
8、验证
[oracle@rh7 ~]$ sqlplus '/as sysdba'
SQL*Plus: Release 11.2.0.1.0 Production on Tue Jul 15 18:01:11 2014
Copyright (c) 1982, 2009, Oracle. All rights reserved.
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
18:01:11 SYS@ prod>select count(*) from scott.emp1;
COUNT(*)
----------
35
Elapsed: 00:00:00.05
@至此，数据恢复完成！
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