Disecting Relationships

by Kevin S
It’s becoming clear that Entity-Relationship models can be just as complicated as Human-Relationships. Fortunately, the journal “Improving Database Design through the Analysis of Relationships” is here to shine some light on the subject. This journal quickly covers all of the basics and dives into a detailed study of relationships. They cover such sticky situations which are often not divulged deeply in textbooks such as high degree relationships, derived relationships, and several more. The four aspects they use as a guide to analyzing a relationship are as follows:

1. Cardinalities or mapping ratios.
2. The degree of a relationship.
3. The recursive nature of a relationship (i.e., an entity participating more than once in a relationship).
4. Interrelationship constraints.

Each of these rules can also be tied into several of the things we are covering in chapter 3. The authors use these guidelines and discuss generalization, specialization, and the overlapping/disjoint rules. Breaking down a relationship into 4 sections to better understand what is happening or what needs to happen is a great way to better create a solid relationship.

I like how this article is written, as it is easy enough for a novice to read and understand yet in depth enough for a seasoned professional to refer to. I did notice that some things such as the notations on the diagrams seem to be out of date, but then again it was written in 1999 so it may have actually been a pioneer to what we are used to seeing now. Overall this was a helpful and informative journal.

DEY, D., STOREY, V. C., & BARRON, M. B. (1999). Improving database design through the analysis of relationships. ACM Transactions on Database Systems, 24(4), 453-486. Retrieved from http://0-delivery.acm.org.opac.library.csupomona.edu/10.1145/340000/331984/p453-dey.pdf?ip= SERVICE&CFID=174516808&CFTOKEN=20726611&__acm__=1350250254_b2e118a4dcd67cd7deb66fc47b46ef08

5 thoughts on “Disecting Relationships

  • October 14, 2012 at 7:03 pm

    The fact that we are currently learning about relationships was really useful to reading this article. In order to analyze a relationship, I also agree that the cardinality, relationship degree, and nature of the relationship, and constraints are all important and necessary when talking about relationships. This article clearly relates to what we learned in class and can prove to be a useful source when learning about relationship analysis.

  • October 14, 2012 at 10:23 pm

    Even though, it was an article written a while ago. I thinks it does relate to class by talking about the important elements to take into consideration when dealing with database relationships. Now, I think that how technology has been changing over the years maybe the concept of relationships main remain the same from back in the days but perhaps with better tools and procedures on how to understand and implement the relations correctly to create a good DB.

  • October 15, 2012 at 12:03 am

    I agree with you in terms that although it is an outdated article, it is informative to the novice and unfamiliar people who is new to the data modeling scene. Unified model language (UML) will constantly change but the essential base of the language will always be in place.

  • October 15, 2012 at 12:03 am

    Understanding relationship has been really tricky for me. The four aspects you listed as a guide to analyzing a relationship helps me grasp the concept. As the author mentions, breaking down a relationship into its most basic form should help me understand it better.

  • October 15, 2012 at 12:37 am

    Learning about entity-relationship models isn’t easy so I would definitely find this journal to be helpful especially for a beginning database student like myself. Learning about these 4 aspects would be helpful for me because it’s important to understand and know how to create relationships between entities in our data models.

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