Sunday, October 28, 2018

Understanding Conceptual vs. Data Modeling Part 3: Don't Conflate Reality and Data

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In Part 1 and Part 2   we explained that between 1975-81, when the E/RM and RDM were introduced, there was no distinction between an inform...
Thursday, October 18, 2018

Understanding Conceptual vs. Data Modeling Parts 1-4

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As parts of a new multipart series, I have rewritten two previous posts that merit a new read. Understanding Conceptual vs. Data Modeli...
Saturday, September 29, 2018

Understanding Conceptual vs.Data Modeling Part 2: E/RM Models Reality, RDM Models Data

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Re-write 10/17/18 Revised 11/1/18 In Part 1 we explained that when the RDM and the E/RM were introduced, the distinct conceptual-logical-...
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 ...
Tuesday, September 11, 2018

RE-WRITE

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See: https://www.dbdebunk.com/2018/09/designation-property-and-assertion.html
Wednesday, August 29, 2018

DISTINCT and ORDER BY Are Not Relational

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“One of the things that confuse SQL users all the time is how DISTINCT and ORDER BY are related in a SQL query ... most people quickly und...
Wednesday, August 15, 2018

Order Is For Society, Not Databases

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8/18/18: I have re-written this post for a better explanation. If you read it prior to the revision, you should re-read it.   “I learned...