先说结论，当遇到业务误删除数据，修改数据错误，想要把数据找回来，将库恢复到之前的某一时间点时，并且你的备份是在DATAGUARD备机上执行的，并且使用的控制文件比较新，控制文件是删除数据后的时间产生的，在做完recover database until time或者until scn时库是无法打开的。

数据库测试版本：11.2 所有操作都是在备机上执行

1.首先在备库做全库备份 RMAN> backup database format '/data/rman/firstbak_%U.bk';

Starting backup at 2022-06-09 10:01:18 using channel ORA_DISK_1 channel ORA_DISK_1: starting full datafile backup set channel ORA_DISK_1: specifying datafile(s) in backup set input datafile file number=00001 name=/data/tstdb/tstdb/system01.dbf input datafile file number=00002 name=/data/tstdb/tstdb/sysaux01.dbf input datafile file number=00003 name=/data/tstdb/tstdb/undotbs01.dbf input datafile file number=00004 name=/data/tstdb/tstdb/users01.dbf channel ORA_DISK_1: starting piece 1 at 2022-06-09 10:01:19 channel ORA_DISK_1: finished piece 1 at 2022-06-09 10:01:22 piece handle=/data/rman/firstbak_050vk3bf_1_1.bk tag=TAG20220609T100118 comment=NONE channel ORA_DISK_1: backup set complete, elapsed time: 00:00:03 channel ORA_DISK_1: starting full 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 2022-06-09 10:01:23 channel ORA_DISK_1: finished piece 1 at 2022-06-09 10:01:24 piece handle=/data/rman/firstbak_060vk3bi_1_1.bk tag=TAG20220609T100118 comment=NONE channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01 Finished backup at 2022-06-09 10:01:24

RMAN>

2.备份控制文件 此时备份的控制文件属于standby类型控制文件 RMAN> backup current controlfile for standby format '/data/rman/ctlforstd1.ck';

Starting backup at 2022-06-09 11:47:55 using target database control file instead of recovery catalog allocated channel: ORA_DISK_1 channel ORA_DISK_1: SID=1197 device type=DISK channel ORA_DISK_1: starting full datafile backup set channel ORA_DISK_1: specifying datafile(s) in backup set