Video description
The logic on which the relational model is based is a two valued logic (2VL). In its attempt to deal with the so called “missing information” problem, however, SQL—more specifically, SQL’s support for “nulls”—is based on a three valued logic (3VL) instead. This session explains in detail why any such approach is doomed to failure. More specifically, it shows why 3VL (a) doesn’t solve the problem, (b) isn’t useful, and (c) can actually be dangerous.
The presentation is divided into three modules. Module I reviews conventional two-valued logic (2VL), examines some of the most immediate differences between it and three-valued logic (3VL), and shows how 3VL inevitably gives rise to errors. Module II goes into more depth on why such errors are inevitable. It also considers the question: Which 3VL are we talking about, anyway? Module III then considers many-valued logics in general, and four-valued logic (4VL) in particular, and discusses a variety of further related points. It also briefly describes an approach to missing information based on 2VL and classical relational theory.
Table of contents
Product information
- Title: Nulls, Three-Valued Logic, and Missing Information
- Author(s):
- Release date: August 2014
- Publisher(s): O'Reilly Media, Inc.
- ISBN: 978149190883
You might also like
video
Python Fundamentals
51+ hours of video instruction. Overview The professional programmer’s Deitel® video guide to Python development with …
video
An Introduction to Set Theory
Everyone knows the relational model is founded on logic and set theory, and moreover that it …
video
Intermediate Python Programming
What do Scrabble cheaters, Shakespearean sonnets, Twitter, and the Astronomy Picture of the Day have to …
video
Algorithms: 24-part Lecture Series
Algorithms, Deluxe Edition, Fourth Edition These Algorithms Video Lectures cover the essential information that every serious …