Figures 5.4, 5.7, and 5.39 each show the decomposition of a ternary relationship. Explain why the entity types SCHEDULE and PRESCRIPTION in Figures 5.4 and 5.7 are shown as base entity types, while the entity type USE in Figure 5.39 is shown as a weak entity type?

QUESTION: Figures 5.4, 5.7, and 5.39 each show the decomposition of a ternary relationship. Explain why the entity types SCHEDULE and PRESCRIPTION in Figures 5.4 and 5.7 are shown as base entity types, while the entity type USE in Figure 5.39 is shown as a...
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Contrast categorization and aggregation?

QUESTION: Contrast categorization and aggregation?   [signinlocker] SOLUTION   In a categorization, an entity that is a member of a category (subclass) must exist in only one of its superclasses. In aggregation, the aggregate (subclass) must contain superclass entities from all SC/sc relationships in which...
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In categorization, what is meant by the property of selective type inheritance?

QUESTION: In categorization, what is meant by the property of selective type inheritance?   [signinlocker] SOLUTION   Members of the category (subclass) selectively inherit attributes and relationships of the superclass entity based on the SC/sc relationship in the categorization in which the member participates. [/signinlocker]
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What is the difference between a total category and a partial category?

QUESTION: What is the difference between a total category and a partial category?   [signinlocker] SOLUTION   A total category occurs when the completeness constraint for all superclasses in the categorization exhibits total participation, while a partial category occurs when the completeness constraint is partial....
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How does categorization differ from specialization?

QUESTION: How does categorization differ from specialization?   [signinlocker] SOLUTION   There is only one superclass and one or more subclasses in a specialization, while a categorization has only one subclass and one or more superclasses. [/signinlocker]
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What is the difference between a specialization hierarchy and a specialization lattice?

QUESTION: What is the difference between a specialization hierarchy and a specialization lattice?   [signinlocker] SOLUTION   In a specialization hierarchy, an entity type can participate as a subclass in only one specialization. In a specialization lattice, an entity type can participate as a subclass...
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Is the use of the “set null” rule applicable to an identifying relationship type? If yes, explain. If no, definitely explain.

QUESTION: Is the use of the “set null” rule applicable to an identifying relationship type? If yes, explain. If no, definitely explain.   [signinlocker] SOLUTION   The Set Null rule cannot be applied to an identifying relationship type because a weak entity type cannot possibly...
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Give examples of types of business rules that are not reflected in a Presentation Layer ER diagram?

QUESTION: Give examples of types of business rules that are not reflected in a Presentation Layer ER diagram?   [signinlocker] SOLUTION   Business rules that cannot be reflected in a Presentation Layer ER diagram include the four categories of business rules (attribute-level business rules, entity-level...
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