Author Question: Briefly identify four important business rules for supertype/subtype relationships. What will be ... (Read 66 times)

khang

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Briefly identify four important business rules for supertype/subtype relationships.
 
  What will be an ideal response?

Question 2

Menu items should be displayed in mixed uppercase and lowercase letters and have a clear, unambiguous interpretation, falls under which category for menu design guidelines?
 
  A) Organization
  B) Selection
  C) Wording
  D) Length


yeungji

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Answer to Question 1

Total specialization, partial specialization, disjoint, and overlap are four business rules for supertype/subtype relationships. The total specialization rule specifies that each entity instance of the supertype must be a member of some subtype in the relationship. The partial specialization rule specifies that an entity instance of the supertype is allowed not to belong to any subtype. The disjoint rule specifies that if an entity instance of the supertype is a member of one subtype, it cannot simultaneously be a member of any other subtype. The overlap rule specifies that an entity instance can simultaneously be a member of two (or more) subtypes.

Answer to Question 2

C



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