Tuesday, January 3, 2017

Understanding the Relational Data Model: A New Series of Papers

"Nowadays, anyone who wishes to combat lies and ignorance and to write the truth must overcome at least five difficulties. He must have:
  1. The keenness to recognize it, although it is everywhere concealed;
  2. The courage to write the truth when truth is everywhere opposed;
  3. The skill to manipulate it as a weapon;
  4. The judgement to select in whose hands it will be effective, and
  5. The cunning to spread the truth among such persons."
--Berthold Brecht
A rather accurate explanation of why it has been so difficult to dispel the misuse and abuse of the Relational Data Model since inception. To the point that most of its core practical benefits have failed to materialize, with the IT industry regressing all the way back to its pre-relational and even pre-database state:
  • Graph DBMSs;
  • XML;
  • JSON;
  • NoSQL;
  • Application-specific databases and DBMSs;
  • "Unstructured data";
  • No integrity enforcement;
  • A cacophony of imperative programming languages rather than declarative data sublanguages (suffixed with QL, just like old non-relational DBMSs were with /R). 

I have been using the proceeds from my monthly blog @AllAnalytics to maintain DBDebunk and keep it free. Unfortunately, AllAnalytics has been discontinued. I appeal to my readers, particularly regular ones: If you deem this site worthy of continuing, please support its upkeep. A regular monthly contribution will ensure this unique material unavailable anywhere else will continue to be free. A generous reader has offered to match all contributions, so please take advantage of his generosity. Thanks.

When I pitched the objective of my last book to a publisher as "to help understand the problems with today's database management", he replied that "there is no interest in understanding, only in succeeding in the job." This is how the truth "is everywhere opposed and remains concealed", the former is not considered a prerequisite for the latter and a top tech advisor to the president believes the future is in college dropouts. Education, knowledge, understanding and reason are the only human obstacles to corporate tyranny and must be eliminated.

DBDebunk is not for those willing to settle for the ad-hoc "cookbook approach" characterizing current practices, but rather for the thinking data professional interested in sound database management grounded in scientific theory. To that end, understanding means a good grasp of the RDM, a formal exposition of which has not yet been published. As I've mentioned several times, this is what David McGoveran has embarked on--the formalization of what he believes was Codd's vision for the RDM, which differs in some important aspects from the current understanding (such as it is) that has taken root following Codd's passing. David's work, to be published in a forthcoming LOGIC FOR SERIOUS DATABASE FOLKS--as was Codd's--is strictly grounded in simple set theory (SST) and first order predicate logic (FOPL), with which the current understanding is not always consistent. It will clarify, refine, extend and, wherever necessary, correct what he believes to have been Codd's vision. @DBDebunk I have undertaken the task of

  • Making as much of the formal theory accessible to thinking data professionals who are genuinely interested in the scientific foundation of the database field;
  • Expose the the advantages and practical benefits of the RDM, many of which failed to materialize due to misunderstanding and poor SQL implementations.
The latest posts and revisions thereof here and my recently published GUIDE TO MISCONCEPTIONS ABOUT DATA FUNDAMENTALS (available to order here) already incorporate David's ideas, several more revisions are pending and so will forthcoming posts. I have updated the search tags to reflect this focus (the old and new ones will apply to all posts, but the new ones only to 2017+ posts).

In my recently published book I referred to revisions of my PRACTICAL DATABASE FOUNDATIONS series of papers that that will incorporate David's work. But on second thought I have decided to leave them as they are, except for corrections and refinements (the book offers a correspondence between what would have been the new and the current papers, enabling the reader to use the current papers as references). Instead, I am starting a new series of short papers that will:
  • Offer what we believe to be a correct interpretation of Codd's RDM;
  • Document misunderstandings in the RDM as currently understood.
The series will start with an analytical survey of Codd's 1969-81 papers, offering an interpretation grounded in SST and FOPL and pointing out strengths, weaknesses and practical implications. The evolution of Codd's thinking will then be used to expose, explain and justify the David's interpretation.

If you find the effort and DBDebunk useful, please purchase our publications and/or donate to support them. 

Happy new year!

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