The Closed World Assumption by C.J. Date


Summary: For relational theory addicts

I always have problem while reviewing C.J. Date’s material. The point here is that the quality, content and way of delivering it are always top noch. No questions here. But on the other hand, when it comes to audience, I think they are targeting specific people and really limited number of specialists. In today’s lazy world, we seek for quick and easy answers and when it comes to deeper understanding of certain topics we tend to avoid getting into details – especially when it takes time.

This is exactly the case here. This material is really important for people who want to get familiar with the foundations of relational databases. In practice, we typically focus only on SQL and database engines, but I think that it’s good to get into basis of relational system if we want to really feel what database are all about. It certainly is the case that you will not become SQL expert after this series, but you will be well aware of some of the limitations in the database world.

There are few things that I miss here in the video. First of all, I would like to be able to download the slides as it definitely would improve the watching experience. Unfortunately, I couldn’t find them on the web page. Another issue here is that video material contains topics you can find in some other videos which should be watched in advance to fully benefit from this one (at least that’s what I assume basing on the content).

Big plus here for packing all the content in reasonable time span. It should be quite easy to find an hour, maybe two (if you want to go carefully over all topics) to watch it.

The content of the video is based on Logic and Databases: The Roots of Relational Theory by C. J. Date but you will also find the definition of closed world as well as samples in the book SQL and Relational Theory: How to Write Accurate SQL Code

Product page:

O’Reilly: The Closed World Assumption