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 weak entity type?   [signinlocker] SOLUTION SCHEDULE and PRESCRIPTION each…

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 it participates. [/signinlocker]

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]

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. [/signinlocker]

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]

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 in more than one specialization. [/signinlocker]

What is the type inheritance property?

QUESTION: What is the type of inheritance property?   [signinlocker] SOLUTION   The type inheritance property involves a subclass inheriting all the attributes of the superclass to which it is related. [/signinlocker]

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 business rules, business rules governing entity deletion, and miscellaneous business…

What is the focus of a Presentation Layer ER Model?

QUESTION: What is the focus of a Presentation Layer ER Model?   [signinlocker] SOLUTION The Presentation Layer ER Model focuses on the presentation of database requirements in a format that can be understood by the end users. [/signinlocker]