I have for a long time thought that anti-virus programs were almost a bigger pain than the viruses that they are supposed to prevent. I got my proof last week when MIcrosoft announced that their OneCare program could blow away your entire Outlook data file or individual Outlook Express mail boxes if you received an attachment with malicious code. Full story at ComputerWorld.
Hilarious. Just hilarious. It wouldn't be so funny if it were irreversible, but fortunately for those affected, it is.
Outlook Express has been replaced with Windows Mail in Vista which keeps separate files for each mail message, preventing the entire database from becoming corrupted (either by a virus, anti-virus, or program bug). I'm not sure how Outlook Full stores mail.
Perhaps this pokes a hole in your opinion that the database is the ultimate data structure (or at least the way it can be stored). One storage place creates one point of failure.