Chapter 4: The Relational Model of Data

Question 1

an attribute that must have a value

Answer 1

required attribute

Question 2

an attribute that does not require a value

Answer 2

optional attribute

Question 3

a primary key composed of more than one attribute

Answer 3

composite identifier

Question 4

an attribute that can be further subdivided to yield additional attributes

Answer 4

composite attribute

Question 5

an attribute that can have only a single value

Answer 5

single-valued attribute

Question 6

attributes that can have many values

Answer 6

multivalued attributes

Question 7

an attribute whose value is calculated from other attributes

Answer 7

derived/computed attributes

Question 8

entities that participate in a relationship

Answer 8

participants

Question 9

used to describe the relationship classification

Answer 9

connectivity

Question 10

express the minimum and maximum number of entity occurrences associated with one occurrence of the related entity

Answer 10

cardinality

Question 11

an entity that exists in the database only when it is associated with another related entity occurrence

Answer 11

existence-dependent

Question 12

an entity can exist apart from all of its related entities

Answer 12

existence-independent

Question 13

the primary key of the related entity does not contain a primary key component of the parent entity

Answer 13

weak relationship/non-identifying relationship

Question 14

exists when the primary key of the related entity contains a primary key component of the parent entity

Answer 14

strong (identifying) relationship

Question 15

the entity is existence-dependent and the entity has a primary key that is partially or totally derived from the parent entity in the relationships

Answer 15

weak entity

Question 16

one entity occurrence does not require a corresponding entity occurrence in a particular relationship

Answer 16

optional participation

Question 17

indicates the number of entities or participants associated with a relationship

Answer 17

relationship degree

Question 18

exists when an association is maintained within a single entity

Answer 18

unary relationship

Question 19

when two entities are associated

Answer 19

binary relationship

Question 20

exists when three entities are associated

Answer 20

ternary relationship

Question 21

when an entity has a relationship with itself

Answer 21

recursive relationship

Question 22

based on repetition of processes and procedures

Answer 22

iterative process