I am working on some example code for some CFUG managers who are demoing our ColdFusion WAF product at their groups. I wanted the demo to be very easy to setup, so I decided to use Apache Derby for the database, since it is embedded with CF8.

Philipp Keller has done some performance test on 4 different database schemas for storing tagged items. Although his article refers to tagging bookmarks, you can tag pretty much anything.