- From: Ashok Malhotra <ashok.malhotra@oracle.com>
- Date: Fri, 25 Oct 2013 09:33:16 -0400
- To: public-propertygraphs@w3.org, "hh >> \"hhalpin@w3.org\"" <hhalpin@w3.org>
Property Graphs differ from other data models such as RDF and Entity-Relationship (E-R) in that they support properties on the arcs (relationships). This makes it easy to represent and query some kinds of information. Here are two examples: EXAMPLE 1: Consider a case where the nodes represent people. Arcs represent "friend" relationships between people. If the arcs have a property such as "started" that indicates when the friend relationship was instantiated, then it is easy to process queries such as: "Show all people that have been friends for more than 2 years". Facebook graph queries have a feature that lets you time-bound queries. I don't know if they use Property Graphs but time properties on arcs would certainly facilitate some of these queries. EXAMPLE 2: Consider a situation where the nodes are students and courses. Students can enroll in many courses and each course can have many students. A student's enrollment in a course would be represented by an arc between the student and the course. The student's grade would then be a property of the arc. (There may be other arc properties such as the student's attendance). Having the grade as a property of the arc makes it simple to ask such queries as "Which students had all A's in all courses?" Does this make sense? Clearly such information can be represented and queried using other data models but, I claim, not so naturally and so efficiently. A claim that has been made is that the data we get from Social Media fits naturally into a Property Graph framework. I don't know if this is true. -- All the best, Ashok
Received on Friday, 25 October 2013 13:33:52 UTC