Database Software

Hi,

I am just begginer with Oracle DB so I do not have a lot knowledge.

I created two backups at April the 8th and April the 10th.

I did following from RMAN.

shutdown immediate
startup mount
configure channel 1 device type disk format '/opt/oracle/backup/std_%U';
backup database
startup

output was:
including current control file in backupset
including current SPFILE in backupset



it created two files: std-0so6l0vn(2 GB) and std_0to6l106 (7 MB).
First question - first file is backup and what is the second file???

Today I created also backup and it also created two files: std_0uo6morg (2GB) and std_0vo6morv (7MB)

Now I want to return backup from 2 days ago (*std-0so6l0vn*) but can't;

I do the the following:
shutdown immediate
startup mount
restore database from '/opt/oracle/backup/std_0so6l0vn'


but getting error - only SPFILE or control file can be restored from autobackup.

How to restore my backup from two days ago? It looks to me so complicated and hardly understandable.

What command to execute from RMAN to succeed in restore?

Thank you