After spending the last few hours reading through Oracle 8i - Recovery Managers User guide and reference as well as various backup scripts for 8i on Windows, I'm a bit confused on some points.

1. 6 days a week we need a hot backup as the system needs to be up 24/7. I have a quick script that I tested last night that uses the following command:

run {
allocate channel ch3 type Disk;
backup full database
include current controlfile
format 'h:\backup\%d_datafile_%s_%p.bak'
tag 'rem3_datafile_daily';
}

and it worked as advertisted.
However, most of the scripts that I've seen that have been written by other people don't use "backup full database" but instead use the command "alter tablespace tablespace_name begin backup"
and then issue the run command and backup the tablespaces.

Which is better?

Additionally in looking at page 5-4 of the Rman users guide, it specifically states "Do not issue ALTER DATABASE BEGIN BACKUP before making an online backup. Why do some of the hotbackup scripts I see issue this command?

The second question I have is that in the backup command syntax it states :
Mount or open the target database. RMAN allows you to make an inconsistent
backup if the database is in ARCHIVELOG mode, but you must apply redo logs
to make the backups consistent for use in restore operations.
I believe I've read elsewhere in the rman manual that you shouldn't backup your redo logs as it would cause database corruption.

I'm trying to understand this quickly as we need the backup solution fast, but I'm a bit confused. Any and all help is much appreciated.


Mark Nelson