oracle preinstall

# cd /etc/yum.repos.d
# wget http://public-yum.oracle.com/public-yum-ol6.repo

oracle-rdbms-server-11gR2-preinstall
oracle-rdbms-server-12cR1-preinstall

echo "proxy=http://Proxy:Port/" >> /etc/yum.conf

No incremental levels for DB INCR in v$rman_backup_job_details

It is advised to use V$RMAN_BACKUP_JOB_DETAILS to identify status of backup jobs. But it is difficult to understand when it was taken full backup of Oracle DB due to in the INPUT_TYPE of the output you can find "DB INCR" value as for FULL Incremental level 0 backups as for Incremental level 1 backups.

You can find way to clarify incremental levels or to find out when was taken FULL backup with the V$BACKUP_SET_DETAILS view.

For instance,
select * from V$BACKUP_SET_DETAILS  where BACKUP_TYPE='I' and INCREMENTAL_LEVEL='0'