- August 2, 2019
Captivating name for CDM?
Read moreI am heads down on my next book, which is a book on the power of the conceptual data model. The book is written for business managers and business analysts, and I therefore hesitate to use the term “conceptual data model”. Years ago, I’ve called this...
50 - March 1, 2019
Can an indicator be NULL?
Read moreAn attribute that is defined as an indicator has only two values, such as Active/Inactive, Yes/No, True/False, and On/Off. I was asked during a training class this week if NULL (empty) can also be a value. Can an indicator attribute have three values, such as Active,...
- February 3, 2019
Ambiguity in Definitions
Read moreI review many data models throughout the year using the Data Model Scorecard technique, and over 95% of the entity and attribute definitions reviewed lack precision. There are certain terms in a definition that, if not explained, automatically make the definition imprecise and vague. The terms...
- January 6, 2019
Is stability an important property for a candidate key on the logical data model?
Read moreA candidate key is an attribute (or set of attributes) that identifies an entity. A candidate key is either a primary key or an alternate key. So for example, in the following Student entity, there are two candidate keys: a primary key on Student Number and...
- December 3, 2018
Learning more about JSON
Read moreOne of my New Year’s Resolutions this year is to learn more about JSON. More specifically, how does JSON act and what are all of the JSON structures, such as nested arrays, which differ from those in our relational world? (I am also currently looking for...