Question

Basic Database: 1. What is an entity supertype, and why is it used? 2. What is a subtype discriminator? Give an example of its use. 3. There are two category symbols: overlapping subtype and nonoverlapping subtypes (disjoint subtype). What is an overlapping subtype? Give an example. What is a disjoint subtype? Give an example. 4. What is the difference between partial completeness and total completeness?

          Basic Database:

1. What is an entity supertype, and why is it used?
2. What is a subtype discriminator? Give an example of its use.
3. There are two category symbols: overlapping subtype and nonoverlapping subtypes (disjoint subtype). What is an overlapping subtype? Give an example. What is a disjoint subtype? Give an example.
4. What is the difference between partial completeness and total completeness?

basic database 1 what is an entity supertype and why is it used 2 what is a subtype discriminator given an example of its use 3 there two category symbols overlapping subtype nonoverlapping 94878

Added by Irene S.

Computer Science and Information Technology

Trishna Knowledge Systems 2018 Edition

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Solved by Expert Nick Johnson

Step 1

An entity supertype is a generic entity type that has a relationship with one or more subtypes. It is used to represent common characteristics shared among related entity types, promote reusability of attributes and relationships, and simplify database design by Show more…

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Basic Database: 1. What is an entity supertype, and why is it used? 2. What is a subtype discriminator? Give an example of its use. 3. There are two category symbols: overlapping subtype and nonoverlapping subtypes (disjoint subtype). What is an overlapping subtype? Give an example. What is a disjoint subtype? Give an example. 4. What is the difference between partial completeness and total completeness?