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Tera-Tom on Teradata Physical Implementation V12-V13 by Tera-Tom Coffing

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Chapter 8 – Logical and Extended Logical Model (ELDM)

“I have found the best way to give advice to your children is to find out what they want and then advise them to do it.”

--Harry S. Truman

Harry Truman was an American president with great logical skills and DEWEY appreciate it! Tables are logically created for all database systems. This is called Logical Modeling. A table that is modeled or normalized will always have a Primary Key. The Primary Key is usually the first column in a table, but the Primary Key column(s) will have three characteristics:

  1. Never be Null
  2. Never change
  3. Never have duplicate values

If a table with a Primary Key has a relationship with another table it will be joined through a Primary Key Foreign Key relationship. ...

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