Thanks for reply.

My question might not be very clear. What I really want to know is how I select a particular backup to do recovery. For example, I have two full tablespace backups -- backup1 and backup2. The backup2 is the most recent one but got removed accidentally, so I need to use backup1 to do recovery. However, I got the error ORA-19505: failed to identify file "......". It seems that Oracle always try to find the most recent backup. Is there any way to define to use the non most recent backup, in this example to use backup1 to do recovery?