Archive Log Mode during Hot Backups
If we talk only about hot backups, and not about restore or recover.
in begin backup mode SCN in header of datafile is frozen and
1. data is updated in datafiles when ever a DML is fired
2. and SCN in updated after finishing backup i.e end backup mode taking the information from checkpoint.
if so
1. why database is required to be in archive log mode for taking hot backup?
2. is the REDO or Archived REDOs are used by datafiles during the backup phase or after completing the backup.
3. if not, then what is the requirement to keep database in archive log mode.
with regards