Exam 3: The Enhanced E-R Model and Business Rules

The process of defining a more general entity type from a set of more specialized entity types is called:

The ________ rule specifies that an entity instance of a supertype is allowed not to belong to any subtype.

A subgrouping of the entities in an entity type that shares common attributes or relationships is called a(n)________.

Describe how subtype discriminators are used when we have overlapping subtypes.

Packaged data models cause projects to take more time to build.

Data models of an existing database are harder for data modelers to read.

In a supertype/subtype hierarchy,attributes are assigned at the highest logical level that is possible in the hierarchy.

Packaged data models use an entity type to store union data.

In packaged data models,all subtype/supertype relationships follow the ________ and ________ rules

Which of the following is NOT true of packaged data models?

Packaged data models are meant to be customized.

Generalization is a top-down process.

The subtype discriminator is a composite attribute when there is a(n):

You should consider using supertype/subtypes when there are ________ that apply to some (but not all)instances of an entity type.