Data Modeling

Question 1

A good business rule is:

Answer 1

(1) declarative
(2) precise
(3) atomic
(4) consistent
(5) expressible
(6) distinct
(7) business-oriented

Question 2

A good data name is:

Answer 2

(1) related to business
(2) meaningful and self-documenting
(3) unique
(4) readable
(5) composed of words from an approved list
(6) repeatable

Question 3

A logical representation of the data from an organization or for a business area, using entities for categories of data and relationships for associations between entities

Answer 3

ENTITY-RELATIONSHIP MODEL

Question 4

A graphical representation of an entity-relationship model

Answer 4

ENTITY-RELATIONSHIP DIAGRAM

Question 5

A person, a place, an object, an event, or a concept in the user environment about which the organization wishes to maintain data

Answer 5

ENTITIES

Question 6

Person, place, object, event, concept (corresponds to a row in a table)

Answer 6

ENTITY INSTANCE

Question 7

Collection of entities (corresponds to a table)

Answer 7

ENTITY TYPE

Question 8

Link between entities

Answer 8

RELATIONSHIP INSTANCE

Question 9

Category of relationship, link between entity types

Answer 9

RELATIONSHIP TYPE

Question 10

Property or characteristic of an entity or relationship type

Answer 10

ATTRIBUTE

Question 11

Often corresponds to a field in a table

Answer 11

ATTRIBUTE

Question 12

Entity is an object that will have many instances in the database.

Answer 12

TRUE

Question 13

Entity is an object that will be composed of multiple attributes. T or F?

Answer 13

TRUE

Question 14

Entity is an object that we are trying to model

Answer 14

TRUE

Question 15

Entity is a user of the database system

Answer 15

FALSE

Question 16

Entity is an output of the database system.

Answer 16

FALSE

Question 17

Property or characteristic of an entity or relationship type

Answer 17

ATTRIBUTE

Question 18

An attribute that has meaningful component parts

Answer 18

COMPOSITE ATTRIBUTE

Question 19

An attribute that cannot be broken down into smaller components that are meaningful to the organization

Answer 19

SIMPLE (OR ATOMIC) ATTRIBUTE

Question 20

An attribute that may take on more than one value for a given entity (or relationship instance)

Answer 20

MULTIVALUED ATTRIBUTE

Question 21

An attribute whose values can be calculated from related attribute values

Answer 21

DERIVED ATTRIBUTE

Question 22

An attribute (or a combination of attributes) that uniquely identifies individual instances of an entity type

Answer 22

IDENTIFIER (KEY)

Question 23

An attribute that could be a key, satisfies the requirements for being an identifier

Answer 23

CANDIDATE IDENTIFIER

Question 24

This relationship exist between tables when only one record of the first table is related to only one record on the second table

Answer 24

ONE-TO-ONE RELATIONSHIP

Question 25

This relationship exist between tables when one record of the first table can be related to one or more records to a second table

Answer 25

ONE-TO-MANY RELATIONSHIP

Question 26

This relationship exists between tables when one record of the first table can be related to one or more records to a second table or vice versa

Answer 26

MANY-TO-MANY RELATIONSHIP

Question 27

Relationships are the glue that holds together the various components of an E-R model

Answer 27

MODELING RELATIONSHIPS

Question 28

A meaningful association between (or among) entity types

Answer 28

RELATIONSHIP TYPE

Question 29

An association between (or among) entity instances where each relationship instance associates exactly one entity instance from each participating entity type

Answer 29

RELATIONSHIP INSTANCE

Question 30

An entity type that associates the instances of one or more entity types and contains attributes that are peculiar to the relationship between those entity instances

Answer 30

ASSOCIATIVE ENTITY

Question 31

How do you know whether to convert a relationship to an associative entity type?

Answer 31

- All the relationships for the participating entity types are "many" relationships - The resulting associative entity type has independent meaning to end users and, preferably, can be identified with a single-attribute identifier - The associative entity has one or more attributes in addition to the identifier - The associative entity participates in one or more relationships independent of the entities related in the associated relationship

Question 32

The number of entity types that participate in that relationship

Answer 32

DEGREE OF RELATIONSHIP

Question 33

Relationship between the instances of a single entity type

Answer 33

UNARY RELATIONSHIP

Question 34

Relationship between the instances of two entity types. The most common type of relationship encountered in data

Answer 34

BINARY RELATIONSHIP

Question 35

Simulataneous relationship among instances of three entity types

Answer 35

TERNARY RELATIONSHIP

Question 36

Recursive relationships

Answer 36

UNARY RELATIONSHIP

Question 37

A rule that specifies the number of instances of one entity that can be associated with each instance of another entity

Answer 37

CARDINALITY CONSTRAINT

Question 38

The minimum number of instances of one entity that may be associated with each instance of another entity

Answer 38

MINIMUM CARDINALITY

Question 39

The maximum number of instances of one entity that may be associated with each instance of another entity

Answer 39

MAXIMUM CARDINALITY