Tuesday, December 13, 2022

NEW "DATA MODELS" 5.1 (t&n)



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 about 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 an email exchange among myself (FP), Chris Date (CJD) and Lee Fesperman (LF) in reaction to Williams' claims that started the series.
Part 2 was my response to a reader's email questioning our dismissal of Williams's claims.
Part 3 was my email exchange with Williams, where he provided his definition of a data model on which I conditioned any discussion with him and where I debunked it.
Part 4 is my response to a reader's comments on Parts 1-3.

Friday, December 2, 2022

NOBODY UNDERSTANDS FURTHER NORMALIZATION 4 (sms)



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 Part 3 we set the matter straight about normalization to 1NF. In this part we do it wit respect to further normalization to 5NF. Non-1NF relations (i.e., with relation-valued attributes) are no longer part of industry practice, so we focus on 2NF-5NF violations. The term further normalization originates with Codd, who initially thought 1NF was sufficient and 2NF-5NF were discovered later (hence, further = beyond 1NF). The industry lumps both under normalization, but the two are distinct (e.g., only further normalization involves redundancy).

What's right/wrong with the following?

“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). First, second, and third normal forms are the basic normal forms in database normalization. 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 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
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