Answer:
1. shutdown the database with normal/emmidiate/transactional
2. modify/include the parameter log_archive_start=true,
log_archive_dest= (location to which the redo log file
group is archived), log_archive_format=(in which format you
want to apper the archive log file)
3. start up the database
2. modify/include the parameter log_archive_start=true,
log_archive_dest= (location to which the redo log file
group is archived), log_archive_format=(in which format you
want to apper the archive log file)
3. start up the database