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Tips to spot subtypes and supertypes
Adding supertypes and subtypes to your logical data model (LDM) helps improve communication, enforce additional rules, and organize thought....
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We live in a world of classifications
Let’s assume your organization has a globally agreed upon definition of a classification: “A way of grouping similar items...
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Define a “Thing”
Trends towards integration in our organizations naturally lead to more abstract concepts. It is not uncommon for example, to...
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A Recursive Riddle
I am cheating just a bit with this challenge, as this is one of the ones from my new book...
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The Person Identifier
A university needs a unique identifier for an individual. There is a Person Identifier assigned by the university to...
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Global Address
A global direct marketing company has hired you to be their data warehouse data modeler. You need to model...
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Aggregation, summarization, and abstraction demystified
As a data modeling expert in your company, you are frequently being asked modeling advice. After dazzling your coworkers...
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Getting physical with subtypes
Subtyping is a powerful communication tool on the logical data model, because it allows the modeler to represent the...
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Subtype key
A subtype inherits its primary key from its supertype. If the supertype is Party for example, we copy the...
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Ontology and Taxonomy
Like many concepts in our field, Ontology and Taxonomy have more than one definition. In addition, these definitions can...