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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, reflecting 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 review references -- reflecting the current understanding of the RDM, distinct from whatever has passed for it in the industry to date -- which explain and correct the misconceptions. You can acquire further 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).

“A non-normalized database is a disorganized one, where nobody has bothered to work out where the facts should be stored. It is like a stack of paper files that has been tossed down the stairs. We are not interested in non-normalized databases.

A normalized database has been organized so that each fact is stored in exactly one place (2nf and greater) and no more than one fact is stored in each place (1nf). In a normalized database there is a place for everything and everything is in its place.

A denormalized database is a normalized database that has had redundancies deliberately re-introduced for some practical gain. Most denormalizing means adding columns to tables that provide values you would otherwise have to calculate as needed. Values are copied from table to table, calculations are made within a row, and totals, averages and other aggregrations are made between child and parent tables.”

--database-programmer.blogspot.com

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(Originally posted on 09/08/2001, slightly revised)

Note: To demonstrate the correctness and stability due to a sound theoretical foundation relative to the industry's fad-driven "cookbook" practices, I am re-publishing as "Oldies But Goodies" material from the old DBDebunk.com (2000-06), so that you can judge for yourself how well my arguments hold up and whether the industry has progressed beyond the misconceptions those arguments were intended to dispel. I may revise, break into parts, and/or add comments and/or references.

“In a world torn by every kind of fundamentalism -- religious, ethnic, nationalist and tribal -- we must grant first place to economic fundamentalism, with its religious conviction that the market, left to its own devices, is capable of resolving all our problems. This faith has its own ayatollahs. Its church is neo-liberalism; its creed is profit; its prayers are for monopolies.”

--Carlos Fuentes

"We as humans have an instinct for creativity and a moral instinct. A good educational system ought to nurture and encourage these aspects of human life and allow them to flourish. But of course that has problems. For one thing, it means that you will encourage challenge of authority and domination. It will encourage questioning of powerful institutions. So the way schools actually function, by and large, there's a very strong tendency that works its way out in the long run and on average, for the schools to have a kind of filtering effect. They filter out independence of thought, creativity, imagination, and in their place foster obedience and subordination."

--Noam Chomsky

"The educated person is not the person who can answer the questions, but the person who can question the answers"

--T. Schick Jr.

 

Follow @DBDebunk Follow @ThePostWest

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, reflecting 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 review references -- reflecting the current understanding of the RDM, distinct from whatever has passed for it in the industry to date -- which explain and correct the misconceptions. You can acquire further 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).

A statement from a 1986 book that "Data are facts represented by values -- numbers, character strings, or symbols -- which carry meaning in a certain context" triggered the following response on Linkedin:

“...In contrast, Date and Darwen (2000) say:

• Domains are the things that we can talk about.
• Relations are the truths we utter about those things.

Thus, the declarative sentence "Fred is in the kitchen." is a fact that links the domains Person[s] and Place[s] with the predicate "is in". The complete relation might be made up of three facts:

• Fred is in the kitchen.
• Mary is in the garden.
• Arthur is in the garden.

This seems to be more precise than the 1986  statement.”

To which the book author responded:

“...back then we did not have the refinement, clarity, nor precision from people like Sjir Nijssen and Terry Halpin regarding facts, or elementary fact sentences, which today you and I know are the bedrock of data modeling. Facts are expressed in sentences (with domains and predicates).”

Unfortunately none of this is sufficiently clear and precise to prevent confusion and it inhibits  understanding of the RDM.