Relational Theory Course Plus Book Collection

In addition to receiving PDF copies of nine of Date’s books, you will have one year of access to all of his books on PebbleU along with his relational theory course! Here is the course description:

There’s a great deal more to relational theory than most people realize. Of course, the relational model, which that theory is built on, is essentially quite simple—you can learn it pretty well in an hour or two, maybe less—but it has amazing depths, and implications that are yet to be fully explored. This one of a kind seminar examines some of those depths and implications. To set the scene, it opens with a preliminary overview of what the relational model and relational DBMSs are really all about—and even that overview might provide a few surprises, if your knowledge of such matters derives only from SQL. It then goes on to build on that foundation, taking closer looks at a series of important topics, including type theory, updating, language design, constraints, database design, views and view updating, temporal data, and missing information.

Top 5 reasons to take this course:

1. Learn relational theory directly from the legend.
2. Self-paced video training, so go at your own speed. You will have access to the course for one year starting from the date of purchase.
3. 70+ topics spanning 10+ hours. Each topic is short (5-15 minute) to maximize learning and retention.
4. Receive interactive access to all eight books for one year.
5. Download PDF copies of all eight books for your future reference.

Domains and Types in Relational Theory and SQL

What’s a domain?  What’s a type?  The original version of the relational model (defined by Codd in 1969) had domains and not types.  The original version of the SQL standard (defined by committee in 1986, but based on work done by Boyce and Chamberlin et al. in the 1970s) had types and not domains.  Later, Codd added types and SQL added domains.  But no two of these constructs—domains per Codd, types per Codd, domains per SQL, types per SQL—are the same thing!  Other researchers, designers, and implementers then got into the act with further definitions of their own, and the picture became, and remains, more confused than ever.  This book is an attempt to clear the air.  To be specific, it argues that: 

• Domains per Codd aren’t really domains in the mathematical sense but are much closer to types in the computing sense, and types per Codd don’t belong in the model at all.
• Types per SQL are really several different concepts all mixed together in confusing ways, and domains per SQL are just a red herring.  
• Properly understood, domains and types are the same thing after all. 

The book justifies these claims by describing and analyzing the pertinent aspects of both SQL and the relational model in detail. 

Database Technology: Nulls Considered Harmful

Essentially all truly general purpose database systems today are based on the relational model of data.  That model was invented by E. F. (“Ted”) Codd in the late 1960s and early 1970s, during his employment at the IBM Research Laboratory in San Jose, California, and it was solidly based on conventional two-valued logic, 2VL.  Unfortunately, those same general purpose database systems today all use the language SQL as their user language—and SQL is based not on 2VL but on what’s called three-valued logic, 3VL, instead, and uses what are called nulls to represent missing information.  In fact, Codd himself subsequently extended his original model to support 3VL and nulls as well.  (Actually, basing SQL on 3VL and adding 3VL to the relational model seem to have occurred in lockstep, as it were.  Certainly both developments occurred at the same place—the IBM San Jose Research Laboratory—at more or less the same time.) 

But 3VL is a disastrously bad basis on which to build databases, or database applications, or database languages.  It’s bad because 3VL doesn’t behave the way reality behaves, which means that results that 3VL says are correct are often not correct in the real world.  Not only that, but SQL’s implementation of 3VL is itself incorrect in places, which means it effectively adds another layer of wrong answers on top of the first.  Bottom line: 

If you have nulls in your database, you’re getting wrong answers. 

This book explains this issue in detail.  It also contains numerous practical suggestions for dealing with the problem. 

The Relational Model for Database Management Version 2 – A Critical Analysis

The relational model of data was invented by one man, E. F. (“Ted”) Codd, during his employment in the late 1960s and early 1970s at the IBM Research Laboratory in San Jose, California. Today, virtually all general purpose database systems are based on that model. But those systems are still a long way from perfect—and a major reason for this sorry state of affairs is that they none of them abide 100% by the prescriptions of the model. To address this problem, Codd subsequently wrote a book, The Relational Model for Database Management Version 2, in which he defined a hugely expanded version of his original model. His aim was to spell out, in vastly more detail than before, exactly what a relational database system is supposed to look like.

Given his track record, anything Codd has to say regarding database matters clearly deserves very careful attention and analysis—and that’s exactly what the present book provides regarding RM/V2 in particular: It describes, explains, and critiques Codd’s new model in all of its myriad aspects. The author, Chris Date, was a close colleague and supporter of Codd’s for many years and was instrumental in getting the word out regarding the original relational model.

Keys, Foreign Keys, and Relational Theory

Keys and foreign keys play a crucial role in relational databases—keys identify the objects of interest, and foreign keys knit those objects together. The basic idea couldn’t be simpler. As so often, however, the devil is in the detail … The fact is, these concepts aren’t quite as straightforward as they might seem on first acquaintance—or, at least, such would appear to be the case, if the literature is anything to go by. In this one of a kind book, noted database author C. J. Date traces the somewhat checkered history of the key and foreign key concepts, shedding some light on what turns out to be, on occasion, a surprisingly murky subject and explaining in detail what proper support should look like in true relational products.

Logic and Relational Theory

As a database professional, you owe it to yourself to understand the basics of formal logic, and you ought to be able to explain the connections between formal logic and database technology.

Fifty Years of Relational, and Other Database Writings

Fifty years of relational. It’s hard to believe the relational model has been around now for over half a century! But it has…

Stating the Obvious, and Other Database Writings

Some things seem so obvious that they don’t need to be spelled out in detail. Or do they?

Database Dreaming Volume I

Along with its companion volume (Database Dreaming Volume II), this book offers a collection of essays on the general topic of relational databases and relational database technology.

Database Dreaming Volume II

Along with its companion volume (Database Dreaming Volume I), this book offers a collection of essays on the general topic of relational databases and relational database technology.

E. F. Codd and Relational Theory, Revised Edition

An examination of all of Codd’s major database publications, explaining the nature of his contribution in depth, and in particular highlighting not only the many things he got right but also some of the things he got wrong.

On Cantor and the Transfinite

The aim of this book is to explain and investigate the claims of Cantor’s in depth (and question them, where appropriate). It’s not a textbook, though; instead, it’s a popular account—it tells a story—and the target audience is interested lay readers, not mathematicians or logicians.

Relational Theory Course: Building on the Foundations

There’s a great deal more to relational theory than most people realize. Of course, the relational model, which that theory is built on, is essentially quite simple—you can learn it pretty well in an hour or two, maybe less—but it has amazing depths, and implications that are yet to be fully explored. This one of a kind seminar examines some of those depths and implications. To set the scene, it opens with a preliminary overview of what the relational model and relational DBMSs are really all about—and even that overview might provide a few surprises, if your knowledge of such matters derives only from SQL. It then goes on to build on that foundation, taking closer looks at a series of important topics, including type theory, updating, language design, constraints, database design, views and view updating, temporal data, and missing information.

“Classroom” (pencil and paper) exercises will reinforce learning.

Prerequisites: Attendees are assumed to be database students or professionals and to have at least a basic familiarity with SQL. Detailed prior knowledge of the relational model as such is not required.