MAN> restore database from tag "TAG20141120T184440";


Starting restore at 26-NOV-14
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=316 device type=DISK
allocated channel: ORA_DISK_2
channel ORA_DISK_2: SID=315 device type=DISK
allocated channel: ORA_DISK_3
channel ORA_DISK_3: SID=317 device type=DISK
allocated channel: ORA_DISK_4
channel ORA_DISK_4: SID=318 device type=DISK


RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of restore command at 11/26/2014 12:25:55
RMAN-06026: some targets not found - aborting restore
RMAN-06023: no backup or copy of datafile 257 found to restore
RMAN-06023: no backup or copy of datafile 256 found to restore
RMAN-06023: no backup or copy of datafile 255 found to restore
RMAN-06023: no backup or copy of datafile 254 found to restore
RMAN-06023: no backup or copy of datafile 253 found to restore
RMAN-06023: no backup or copy of datafile 252 found to restore
RMAN-06023: no backup or copy of datafile 251 found to restore
.....
...
..


一开始认为是备份集或脚本的问题，各种方法去验证备份集和脚本，发现都没有问题，后来发现是incarnation的问题


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     109431336        PARENT  71120748   Sep 14 2009 23:49:21
2       2       PROD     109431336        PARENT  71126589   Sep 14 2009 23:50:00
3       3       PROD     109431336        PARENT  200149578  Jan 11 2010 23:40:19
4       4       PROD     109431336        CURRENT 133578841218 Oct 28 2014 09:39:02

恢复到incarnation 3
RMAN>reset database to incarnation 3;

成功恢复
RMAN> restore database from tag "TAG20141120T184440";


incarnation（化身）解释：

---------incarnation 1------->
                         |
                          ---------incarnation 2------>
                                           |
                                            -----------incarnation 3---->
-------------------------------SCN------------------------------------------>


每一个incarnation都是一个不同的版本，每一次resetlogs 就会使 incarnation + 1，
要想做不完全恢复时，一定要了解备份介质是在哪一个incarnation基础上做的备份。
这个特性有点类似于vmware的快照功能（没有用过的同学可能就不知了）