rman恢復時ORA-01152: file 1 was not restored from a sufficiently old backup

ORA-01547: warning: RECOVER succeeded but OPEN RESETLOGS would get error below
ORA-01152: file 1 was not restored from a sufficiently old backup 
ORA-01110: data file 1: '/oradata/datafile1/system01.dbf'

RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of recover command at 07/15/2015 17:50:56
RMAN-06054: media recovery requesting unknown archived log for thread 1 with sequence 2220 and starting SCN of 8429237




解決方法：
是由於controlfile裡所記錄的scn與datafile裡的scn不一致。後來查了一下發現restore controlfile時取了一份較早的檔案。
於是：
1.shutdown immediate
2.startup nomount
3.rman 下 set dbid
4.重新restore 一份較晚的controlfile.
5.alter database mount;
6.重新recover database 到原先指定的時間點，這裡不用restore database是因為原來已經restore成功了
7.alter database open resetlogs;