Database Design Ch. 7 Study Guide

Business organizational charts are often modeled as a Hierarchical relationship. True or False?

-True

Which of the following can be added to a relationship? -An optional attribute can be created -A composite attribute -An attribute -An arc can be assigned

-An arc can be assigned

To visually represent exclusivity between two or more relationships in an ERD you would most likely use an ________. -Arc -Relationship -Attribute -UID

-Arc

Every business has restrictions on which attribute values and which relationships are allowed. These are known as: -Constraints -Relationships -Entities -Attributes

-Constraints

Which of the following would best be represented by an arc? -TEACHER (Female, Bob) -PARENT (Girl, Bob) -DELIVERY ADDRESS (Home, Office) -STUDENT (Grade A student, Average Student)

-DELIVERY ADDRESS (Home, Office)

Arcs are used to visually represent _________ between two or more relationships in an ERD. -Differences -Inheritance -Sameness -Exclusivity

-Exclusivity

A recursive relationship must be Mandatory at both ends. True or False?

-False

A single relationship can be both Recursive and Hierarchical at the same time. True or False?

-False

All relationships participating in an arc must be mandatory. True or False?

-False

Arcs are Mandatory in Data modeling. All ERD's must have at least one Arc. True or False?

-False

Cascading UIDs are a feature often found in what type of Relationship? -Invalid Relationship -Recursive Relationship -General Relationship -Heirarchical Relationship

-Heirarchical Relationship

A Recursive Relationship is represented on an ERD by a/an: -Single Toe -Pig's Ear -Crow's Foot -Dog's Tail

-Pig's Ear

A relationship between an entity and itself is called a/an: -Recursive Relationship -Invalid Relationship -Heirarchical Relationship -General Relationship

-Recursive Relationship

Which of the following would best be represented by an arc? -STUDENT (senior, male) -STUDENT (Grade A student, Average Student) -STUDENT (graduating, female) -STUDENT (University, Technical College)

-STUDENT (University, Technical College)

A Hierarchical relationship is a series of relationships that reflect entities organized into successive levels. True or False?

-True

A particular problem may be solved using either a Recursive Relationship or a Hierarchical Relationship, though not at the same time. True or False?

-True

An arc can often be modeled as Supertype and Subtypes. True or False?

-True

Arcs model an Exclusive OR constraint. True or False?

-True