Can someone please explain to me what is the benefit of using database (like MySQL) with XML documents. It is not clear to me why would it be cool to store XML tagged content into database.

Inspiration for this question was Kevin Yanks article Get XSL To Do Your Dirty Work. If you look at Figure 8 you can see how it should be done. But this seems illogical. You either use XML or database. Or am I wrong here?

Please list benefits of doing that and drawbacks too. Thanks

P.S.: It's a great article though, Kevin.