I have done a full RMAN backup plus archivelog using

backup tag=MASTER_BACKUPSET_27NOV08 database spfile include current controlfile plus archivelog;

now I want to keep it as a master copy forever using KEEP option.

change backup tag 'MASTER_BACKUPSET_27NOV08' keep forever logs;

however i am getting this.
.
.
RMAN-03002: failure of KEEP command at 11/28/2008 11:21:30
RMAN-06530: CHANGE ... KEEP not supported for backup set which contains archive logs


If i am to do a full backup up again without the 'PLUS archivelog'
backup tag=MASTER_BACKUPSET_27NOV08 database spfile include current controlfile

Will I be able to restore and recover the database back to original some point in the future using the that backup without the archivelogs around that time?

I guess what I am trying to ******** is whether a FULL ONLINE RMAN backup is a consistant backup or not and can be be used with archivelogs available.

Thanks in advance for your help..