HierarchyId in SQL Server

I just had a collegue send an email out to the team regarding the new HierarchyId in SQL server. I wanted to share with you my response to that. I'll start with His email and then follow up with my response.

Original Email:

I’m a bit worried by posts like this:

http://www.sqlskills.com/blogs/simon/post/SQL-Server-2008-HierarchyId-whats-the-point.aspx

Does anyone know of a strong argument for using HierarchyId?

My Response:

Microsoft’s documentation on HierarchyId is found here:

http://msdn.microsoft.com/en-us/library/bb677290.aspx

I think conceptually, someone at Micro$oft decided that they wanted a new (data-centric) way of managing information in a hierarchy tree. It sounds like they wanted a one-stop-shop way of being able to parse and determine children and manage nodes that were aware of the current data structure. Just from the last few minutes of research, I cannot say that I’m sold on it seeing as I come from an “old school” of managing these types of relationships – good old fashion data structures and a good data model that logically describes what you are trying to convey. Adding an additional ID (and management layer) which lays the management responsibility on the database, in my opinion, reduces your flexibility and ability to manage the data as you need. What’s the old saying: some are willing to give up freedom for security/convenience – sounds like other things happening on a national level – ah, but I digress! (Enough on that)