Database Software

I have a question but don't know what it is?

I am using hot backup and the backup directory is "/u02/db/backup/RMAN" and all the backups should be here after schedule daily or weekly backup. As I think all the backup files should be included the followings:
1) control file
2) spfile file
3) data files
4) archvie log files

However, I found that there are somes files named as "c-1357907388-20081015-00" & "c-1357907388-20081015-01" under directory "/u02/oracle/uat/uatdb/9.2.0/dbs" after backup each times. These 2 are found after daily backup last night.

Any ideas?

---------- Here is daily backup script -------------

run
{
CONFIGURE CONTROLFILE AUTOBACKUP ON;
CONFIGURE RETENTION POLICY TO RECOVERY WINDOW OF 7 DAYS;
allocate channel ch1 type disk format '/u02/db/backup/RMAN/backup_%d_%t_%s_%p_%U.bck';
backup incremental level 1 cumulative database plus archivelog delete all input;
delete noprompt obsolete;
delete noprompt archivelog all backed up 2 times to disk;
backup current controlfile;
backup spfile;
release channel ch1;
}
-----------------------------------------------------


Thanks,
Amy