Week 4 - ISM 4212

The ________ rule specifies that an entity can be a member of only one subtype at a time. Select one: a. removal b. exclusion c. disjoint d. inclusion

Disjoint

A ________ addresses whether an instance of a supertype may simultaneously be a member of two or more subtypes. Select one: a. total specialization b. disjoint rule c. disjointedness constraint d. partial specialization

Disjointedness constraint

Creating a data model from a packaged data model requires much more skill than creating one from scratch. -- (T/F)

False

Generalization is a top-down process. -- (T/F)

False

The ________ rule states that an entity instance can simultaneously be a member of two (or more) subtypes. Select one: a. disjoint b. total specialization c. partial specialization d. overlap

Overlap

The ________ rule specifies that an entity instance of a supertype is allowed not to belong to any subtype. Select one: a. partial specialization b. disjointedness c. total specialization d. semi-specialization

Partial specialization

Which of the following is a generic entity type that has a relationship with one or more subtypes? Select one: a. Class b. Subgroup c. Megatype d. Supertype

Supertype

The ________ rule specifies that each entity instance of the supertype must be a member of some subtype in the relationship. Select one: a. total convergence b. semi-specialization c. partial specialization d. total specialization

Total specialization

Packaged data models are as flexible as possible, because all supertype/subtype relationships allow the total specialization and overlap rules. -- (T/F)

True

An entity cluster is: Select one: a. a useful way to present data for a small and fairly simple organization. b. a set of one or more entity types and associated relationships grouped into a single abstract entity type. c. a formal method for specifying attributes of related entities. d. a way of developing more granular views of the data model.

a set of one or more entity types and associated relationships grouped into a single abstract entity type.

The property by which subtype entities possess the values of all attributes of a supertype is called: Select one: a. attribute inheritance. b. hierarchy reception. c. class management. d. generalization.

attribute inheritance.

A(n) ________ constraint is a type of constraint that addresses whether an instance of a supertype must also be an instance of at least one subtype. Select one: a. weak b. completeness c. disjoint d. overlap.

completeness

The process of defining a more general entity type from a set of more specialized entity types is called: Select one: a. extrapulation. b. specialization. c. generalization. d. normalization.

generalization.

In a supertype/subtype hierarchy, each subtype has: Select one: a. many supertypes. b. only one supertype. c. at most two supertypes. d. at least one subtype

only one supertype.

Packaged data models: a. allow partial specialization. b. are ready to use right out of the box. c. cannot be used for most applications. d. require customization

require customization

The process of defining one or more subtypes of a supertype and forming relationships is called: Select one: a. creating discord. b. specialization. c. selecting classes. d. generalization.

specialization.

An attribute of the supertype that determines the target subtype(s) is called the: Select one: a. disjoint indicator. b. subtype decision. c. subtype discriminator. d. determinant.

subtype discriminator

Subtypes should be used when: Select one: a. there are attributes that apply to some but not all instances of an entity type. b. a recursive relationship is needed. c. supertypes relate to objects outside the business. d. the instances of a subtype do not participate in a relationship that is unique to that subtype.

there are attributes that apply to some but not all instances of an entity type.

A generic or template data model that can be reused as a starting point for a data modeling project is called a(n): Select one: a. universal data model. b. packaged data model. c. enterprise data model. d. collection data model.

universal data model.