Parallels disk image tough on Time Machine?

I remember reading that an application like Outlook could be tough on Time Machine because it uses one big data file that changes often, and so Time Machine has to keep wirting this entire file to the external disk (unlike Mail.app that, I believe, keeps its data as individual files so that only the relatively smaller files that change get backed up).

If this is correct, does this mean that the Parallels entire disc image must be written and rewritten every hour (or whatever) by Time Machine because it's essentually one potentially huge file (if that's how Parallels does it)?

Is it possible to backup, say, Outlook's data (from inside Parallels running XP) to a separate disk as you normally would running XP natively -- that is, saving the data separate and "outside" of the disk image Parallels work with?

If you're running Outlook inside Parallels, there's at least a couple of options when excluding your virtual machine folder(s) from Time Machine:

1) Use the 'snapshot' feature in Parallels so that you can recover to an earlier version of your Outlook mailbox in the event of problems. The only issue is that you effectively roll-back the entire VM so you may lose other changes you wanted to keep.

2) Use something like OutBack Plus or ABF Outlook Backup to take direct backups of your Outlook settings & data which you then save somewhere safe outside the VM. That could be a shared folder from your Mac, mapped thru to the virtual machine, or maybe a network share.

I use VMWare Fusion and backup my Outlook data & config using the ABF software to a NAS device.