Note: In "Setting Matters Straight" posts I debunk online pronouncements that involve fundamentals which I first post on LinkedIn. The purpose is to induce practitioners to test their foundation knowledge against our debunking, where we explain what is correct and what is fallacious. For in-depth treatments check out the POSTS and our PAPERS, LINKS and BOOKS (or organize one of our on-site/online SEMINARS, which can be customized to specific needs). Questions and comments are welcome here and on LinkedIn.

(Continued from Part 1)

What's right/wrong about this database picture?

“So, what is this theory of normal forms? It deals with the mathematical construct of relations (which are a little bit different from relational database tables). The normalization process consists of modifying the design through different stages, going from an unnormalized set of relations (tables), to the first normal form, then to the second normal form, and then to the third normal form.”

--Vertabelo.com

Misconceptions

• All database relations are, mathematically, relations, but not all mathematical relations are database relations.
• The tabular structure play practically no role in RDM.
• In practice there is no normalization (to 1NF) and there should not be further normalization (to 5NF).
• Further normalization does not go from 2NF sequentially through 3NF and 4NF to 5NF.
  

Note: "Then & Now" (t&n) is a new version of what used to be the "Oldies but Goodies" (obg) series. To demonstrate the superiority of a sound theoretical foundation relative to the industry's fad-driven "cookbook" practices, as well as the evolution/progress of RDM, I am re-visiting my 2000-06 debunkings, bringing them up to my with my knowledge and understanding of today. This will enable you to judge how well my arguments have held up and appreciate the increasing gap between scientific progress and the industry’s stagnation, if not outright regress.

This is a re-published series of several DBDebunk 2001 exchanges on Simon Wlliams' so-called "Associative Model of Data" (AMD), academic claims of its superiority over RDM ("The Associative Data Model Versus the Relational model") and predictions of the demise of the latter ("The decline and eventual demise of the Relational Model of Data").

Part 1 was the email exchange among myself (FP), Chris Date (CJD) and Lee Fesperman (LF) in reaction to Simon Williams' claims that started the series. Part 2 is my response to a reader's email questioning our dismissal of Williams's claims.  (The reader's comments are in quotes.)

Note: In "Setting Matters Straight" posts I debunk online pronouncements that involve fundamentals which I first post on LinkedIn. The purpose is to induce practitioners to test their foundation knowledge against our debunking, where we explain what is correct and what is fallacious. For in-depth treatments check out the POSTS and our PAPERS, LINKS and BOOKS (or organize one of our on-site/online SEMINARS, which can be customized to specific needs). Questions and comments are welcome here and on LinkedIn.

What's right/wrong with this database picture?

“Normalization in relational databases is a design process that minimizes data redundancy and avoids update anomalies. Basically, you want each piece of information to be stored exactly once; if the information changes, you only have to update it in one place. The theory of normal forms gives rigorous meaning to these informal concepts. There are many normal forms. In this article, we’ll review the most basic:
First normal form (1NF)
Second normal form (2NF)
Third normal form (3NF)
There are normal forms higher than 3NF, but in practice you usually normalize your database to the third normal form or to the Boyce-Codd normal form, which we won’t cover here.”

                                                                     --Vertabelo.com

Note: "Then & Now" (T&N) is a new version of what used to be the "Oldies but Goodies" (OBG) series. To demonstrate the superiority of a sound theoretical foundation relative to the industry's fad-driven "cookbook" practices, as well as the evolution/progress of RDM, I am re-visiting my 2000-06 debunkings, bringing them up to my with my knowledge and understanding of today. This will enable you to judge how well my arguments have held up and appreciate the increasing gap between scientific progress and the industry’s stagnation, if not outright regress.

“Codd's aim was to free programmers from having to know the physical structure of data. Our aim is to free them in addition from having to know its logical structure.”

                                                 --Simon Williams, LazySoft

This series is a re-publication of several DBDebunk 2001 posts in response to Simon Wlliams' so-called "Associative Model of Data", academic claims of superiority over RDM ("The Associative Data Model Versus the Relational model") and predictions of the demise of the latter ("The decline and eventual demise of the Relational Model of Data").

Part 1 is the email exchange among myself (FP), Chris Date (CJD) and Lee Fesperman (LF) in reaction to Williams' claims that started the whole thing.

Q: “I have done data normalization on dummy data and would like to know if I did it correctly. If it is done correctly, I would also like to ask two things below, because it is about 3NF.

1NF: This table should be 1NF. 

2NF: I selected composite key (userID and Doors) as they represent minimal candidate key and got three tables applying FD rule.

3NF: Applying the rule of transitive dependency on 1st table in 2NF, I got out 4 tables (showing only first two, because the last two remain unchanged).

Questions: Is this database normalisation correct? If not could you point me where I did mistake? If answer on first question is True: Should the last table in 3NF be transformed into two tables, given it is not in correct Third normal form. Two non-key atributes have FD keycode -> accessGroup.”

Note: In "Setting Matters Straight" posts I debunk online pronouncements that involve fundamentals which I first post on LinkedIn. The purpose is to induce practitioners to test their foundation knowledge against our debunking, where we explain what is correct and what is fallacious. For in-depth treatments check out the POSTS and our PAPERS, LINKS and BOOKS (or organize one of our on-site/online SEMINARS, which can be customized to specific needs). Questions and comments are welcome here and on LinkedIn.

In a previous SMS post I debunked an attempt to express something important about database practice that was handicapped by lack of foundation knowledge. Here is another example.

“This Codd guy might have been onto something. Unfortunately, normalization is usually taught in a somewhat backwards, overly technical way. If you start with concepts, connections between them and details about them, you usually are already at a fairly high normal form without going through any formal normalization steps.”

--LinkedIn.com

Note: "Then & Now" (T&N) is a new version of what used to be the "Oldies but Goodies" (OBG) series. To demonstrate the superiority of a sound theoretical foundation relative to the industry's fad-driven "cookbook" practices, as well as the evolution/progress of RDM, I am re-visiting my 2000-06 debunkings, bringing them up to my with my knowledge and understanding of today. This will enable you to judge how well my arguments have held up and appreciate the increasing gap between scientific progress and the industry’s stagnation, if not outright regress.

This was an email exchange with a reader, first published as ON ON-THE-FLY THINKING in March 2005.

“From a quick one-page marketing article:

"Relational databases are one to two orders of magnitude too slow."
--Michael Stonebreaker, quoted in Data on the Fly, Forbes

The quote is directly from the company's owner who "...created two well-known relational database systems, Ingres and Postgres." Further from the reporter:

"Unlike traditional database programs, Streambase analyzes data without storing it to disk, performing queries on data as it flows."

Hmmm... didn't know that the Relational Model of Data specifically proscribed in-memory implementations.”