by Jon Witts.
Hi Rick,
With those three things backed up it is possible to perform a complete system restore (even to another server if needed) without the need of going to get any other files.
If you did not have a backup of the main moodle web files you would need to go and find the exact same version of the moodle files plus any plugins and themes you may have installed before you could restore. Depending upon the age of your moodle install this could prove difficult.
My view is; "Why make it hard for yourself?" - if you have all three you know that you can restore everything if the worst happens!
Jon