SQL and Relational Theory, 3rd Edition

Appendix F

No SQL and Relational Theory

Just say no!

—Nancy Reagan (1982)

Note: This appendix is based in part on material from two papers that originally appeared in the NoCOUG Journal (the journal of the Northern California Oracle User Group):

• C. J. Date and Hugh Darwen: “No to SQL! No to NoSQL!” (interview by Iggy Fernandez), NoCOUG Journal 27, No. 3 (August 2013), www.nocoug.org/Journal/NoCOUG_Journal_201308.pdf.

• C. J. Date: “Some Comments on Iggy Fernandez’s Paper The Rise and Fall of the NoSQL Empire,” NoCOUG Journal 29, No. 2 (May 2015), www.nocoug.org/Journal/NoCOUG_Journal_201505.pdf.

The material is reused here by permission.

I said in Chapter 1 that we’d be concerned in this book with principles, not products, and foundations, not fashion or fads. In this appendix, however, I’m going to go back on that promise a little. As I’m sure you know, in recent years there’s been a major upsurge of interest in what are known generically as NoSQL systems. And, as so often happens when something suddenly becomes fashionable for some reason, this new development has been surrounded by a fair degree of confusion. In this appendix, I’d like to try to clear up some of that confusion, if I can. In particular, I’d like to try to clarify the relationship—to the extent that any such relationship exists—between the NoSQL movement and what is after all a major topic for the present book, viz., relational theory.

The first confusion arises in connection with the very name “NoSQL.” Naïvely, ...