Showing posts with label NULL. Show all posts
Showing posts with label NULL. Show all posts
Thursday, May 2, 2024

SMS: PRIMARY KEYS & INDEXES

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I am working on entirely new papers (not re-writes) in the PRACTICAL DATABASE FOUNDATIONS series. I have already published two: THE FIRST NO...
Tuesday, July 25, 2023

NULL & THE "2ND ADDRESS LINE" (sms)

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Note: In "Setting Matters Straight" posts I debunk online pronouncements that involve fundamentals which I first post on Linked...
Monday, June 19, 2023

PREDICATE LOGIC, SEMANTICS AND RDM (sms)

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Note: In "Setting Matters Straight" posts I debunk online pronouncements that involve fundamentals which I first post on Linked...
Saturday, April 8, 2023

MISSING DATA: RDM VS SQL -- A REAL WORLD COMPARISON (t&n)

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Note: "Then & Now" (t&n) is a new version of what used to be the "Oldies but Goodies" (OBG) series. To demonstra...
Wednesday, July 13, 2022

MISSING DATA AND MULTI-RELATION QUERY RESULTS (t&n)

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Note: "Then & Now" (T&N) is a new version of what used to be the "Oldies but Goodies" (OBG) series. To demons...
Sunday, March 6, 2022

RELATIONSHIPS: UNIQUENESS & ATTRIBUTE CONSTRAINTS (tyfk)

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Note: Each "Test Your Foundation Knowledge" post presents one or more misconceptions about data fundamentals. To test your know...
Saturday, February 19, 2022

NO UNDERSTANDING WITHOUT FOUNDATION KNOWLEDGE PART 6: DEBUNKING AN ONLINE EXCHANGE 5 (obg)

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Note: To demonstrate the correctness and stability offered by a sound theoretical foundation (relative to the industry's fad-driven ...
Sunday, February 13, 2022

NO UNDERSTANDING WITHOUT FOUNDATION KNOWLEDGE PART 5: DEBUNKING AN ONLINE EXCHANGE 4 (obg)

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Note: To demonstrate the correctness and stability due to a sound theoretical foundation relative to the industry's fad-driven ...
Friday, January 21, 2022

READ MY LIPS: IF THERE'S NULLs, IT'S NOT RELATIONAL

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“Let's say I want to store a list of movies that are stored on iTunes. For simplicity, we'll just store a few fields so that the fil...
Saturday, January 8, 2022

NO UNDERSTANDING WITHOUT FOUNDATION KNOWLEDGE PART 2: DEBUNKING AN ONLINE EXCHANGE 1 (obg)

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Note: To demonstrate the soundness and stability conferred by a sound theoretical foundation (relative to the industry's fad-driven ...
Saturday, January 16, 2021

OBG: Missing Data -- Many-valued Logics and NULL Part 2

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Note: To demonstrate the correctness and stability due to a sound theoretical foundation relative to the industry's fad-driven "co...
Saturday, January 9, 2021

OBG: Missing Data -- Many-valued Logics and NULL Part 1

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Note: To demonstrate the correctness and stability of a sound theoretical foundation relative to the industry's fad-driven "cookbo...
Friday, November 27, 2020

OBG: Missing Data -- "Horizontal Decomposition" Part 2

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Note: To demonstrate the correctness and stability of a sound foundation relative to the industry's fad-driven "cookbook" pra...
Sunday, November 22, 2020

OBG: Missing Data -- "Horizontal Decomposition" Part 1

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Note: To demonstrate the correctness and stability of a sound foundation relative to the industry's fad-driven "cookbook" pra...
Saturday, October 17, 2020

Understanding Codd's 12 Rules for RDBMS

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In response to an online publication of a book appendix regurgitating Codd's 12 famous rules (some of which were, typically, incorrect[ ...
Thursday, May 28, 2020

No Such Thing As "Current Relational Data Models"

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“... the concept of a state group is indeed a missing modeling concept in relational/current data models...” Thus in a LinkedIn exchange....
Tuesday, September 18, 2018

Don't Conflate/Confuse Primary Keys, PK Constraints, and Indexes

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“What is the difference between an index and a key? How are they related?” “There seams to be some confusion between what a Primary Key ...
Wednesday, July 4, 2018

N-ary vs. Binary Relations: Anatomy of a Compound Misconception

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Note: This is a re-write of an older post, to bring it into line with the McGoveran formalization and interpretation [ 1 ] of Codd's t...
Sunday, April 22, 2018

A New Understanding of Keys Part 2: Kinds of Keys

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Note: This the second of three re-writes of older posts to bring them in line with McGoveran's formalization and interpretation[ 1 ] of...
8 comments:
Saturday, April 1, 2017

"NULL Value" is a Contradiction in Terms

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There is nothing wrong with Hugo Kornelis' picture of SQL NULL in NULL: The database's black hole . In fact, I recommend the series ...
14 comments: