Friday, February 12, 2021

(TYFK) What Is a Relational Database and Why Is It Important?



Note: Each "Test Your Foundation Knowledge" post presents one or more misconceptions about data fundamentals. To test your knowledge, first try to detect them, then proceed to read our debunking, which is based on the current understanding of the RDM, distinct from whatever has passed for it in the industry to date. If there isn't a match, you can acquire the knowledge by checking out our POSTS, BOOKS, PAPERS, LINKS (or, better, organize one of our on-site SEMINARS, which can be customized to specific needs).

“The most popular data model in DBMS is the Relational Model. It is more scientific a model than others. This model is based on first-order predicate logic and defines a table as an n-ary relation. The main highlights of this model are:
  • Data is stored in tables called relations.
  • Relations can be normalized.
  • In normalized relations, values saved are atomic values.
  • Each row in a relation contains a unique value.
  • Each column in a relation contains values from a same [sic] domain.”
--What is a relational database and why is it important, Quora.com

------------------------------------------------------------------------------------------------------------------

SUPPORT THIS SITE
DBDebunk was maintained and kept free with the proceeds from my @AllAnalitics column. The site was discontinued in 2018. The content here is not available anywhere else, so if you deem it useful, particularly if you are a regular reader, please help upkeep it by purchasing publications, or donating. On-site seminars and consulting are available.Thank you.

LATEST UPDATES
-12/24/20: Added 2021 to the
POSTS page

-12/26/20: Added “Mathematics, machine learning and Wittgenstein to LINKS page

LATEST PUBLICATIONS (order from PAPERS and BOOKS pages)
- 08/19 Logical Symmetric Access, Data Sub-language, Kinds of Relations, Database Redundancy and Consistency, paper #2 in the new UNDERSTANDING THE REAL RDM series.
- 02/18 The Key to Relational Keys: A New Understanding, a new edition of paper #4 in the PRACTICAL DATABASE FOUNDATIONS series.
- 04/17 Interpretation and Representation of Database Relations, paper #1 in the new UNDERSTANDING THE REAL RDM series.
- 10/16 THE DBDEBUNK GUIDE TO MISCONCEPTIONS ABOUT DATA FUNDAMENTALS, my latest book (reviewed by Craig Mullins, Todd Everett, Toon Koppelaars, Davide Mauri).

USING THIS SITE
- To work around Blogger limitations, the labels are mostly abbreviations or acronyms of the terms listed on the
FUNDAMENTALS page. For detailed instructions on how to understand and use the labels in conjunction with the that page, see the ABOUT page. The 2017 and 2016 posts, including earlier posts rewritten in 2017 were relabeled accordingly. As other older posts are rewritten, they will also be relabeled. For all other older posts use Blogger search.
- The links to my columns there no longer work. I moved only the 2017 columns to dbdebunk, within which only links to sources external to AllAnalytics may work or not.

SOCIAL MEDIA
I deleted my Facebook account. You can follow me:
- @DBDdebunk on Twitter: will link to new posts to this site, as well as To Laugh or Cry? and What's Wrong with This Picture? posts, and my exchanges on LinkedIn.
- The PostWest blog for monthly samples of global Antisemitism – the only universally acceptable hatred left – as the (traditional) response to the existential crisis of decadence and decline of Western  civilization (including the US).
- @ThePostWest on Twitter where I comment on global #Antisemitism/#AntiZionism and the Arab-Israeli conflict.

------------------------------------------------------------------------------------------------------------------

Misconceptions

  • The RDM is not the most popular data model.
  • There are no "others" -- no other data models that comply with the definition by Codd, who invented the concept.
  • By definition a data model cannot be "less scientific".
  • The RDM is not based on just FOPL, which does not define "a table as an n-ary relation", and relations don't have rows and columns.
  • Data is stored neither in tables, nor in relations;
  • Relations do not require normalization (if they do, they are not relations).
  • Value atomicity is misunderstood.

 

Note: I will not publish or respond to anonymous comments. If you have something to say, stand behind it. Otherwise don't bother, it'll be ignored.

 

References

Data Sublanguage vs. SQL

"Multi-model DBMSs" is an Empty Set

Theory: As Far From Religion As One Can Get

What Is a Data Model and What It Is Not

Understanding Relations: Tables, So What?

What Relations Really Are and Why They Are Important

Data and Meaning: The RDM Is Applied Theory

Physical Independence series

Normalization and Further Normalization series

First Normal Form in Theory and Practice series

Simple Domains and Value Atomicity




No comments:

Post a Comment

View My Stats