- From: Alan Ruttenberg <alanruttenberg@gmail.com>
- Date: Mon, 9 Mar 2009 15:26:58 -0400
- To: W3C OWL Working Group <public-owl-wg@w3.org>
I've followed up with Marijke about the issue of hasKey. The issue for her is that "key" has a specific meaning in the ER and Conceptual data modeling worlds and that the common notion is that keys are functional. Because of the overlap of our user base with that one, she suggests at least a short note in syntax commenting on the difference between our keys and what people will be familiar with, and suggests that one of our user facing documents show how to map keys in this other sense to our keys (i.e. hasKey + functional properties). In support of her view she offers two citations: "The Entity-Relationship Model-Toward a Unified View of Data",by Peter Pin-Shan Chen, that she considers a foundational paper in the area, which says, among other things: "Basically, an entity key is a group of attributes such that the mapping from the entity set to the corresponding group of value sets is one-to-one." This paper is available at http://faculty.ndhu.edu.tw/~wpyang/DatabaseTeachingCenter/File2AdvancedDB/4References/erd.pdf "Information Modeling and Relational Databases", ed. 2008, By Terry Halpin, Tony Morgan, from which she points at, among other places, figure 5.16 and the description on page 174-175. This book is on google books and the following link should bring you to the figure in question: http://tinyurl.com/d8gshx Regards, Alan
Received on Monday, 9 March 2009 19:27:39 UTC