Chapter 3 (ER Model)

Question 1

is a basic concept for the E R model. specific things or objects in the mini-world that are represented in the database.

Answer 1

Entities

Question 2

properties used to describe an entity

Answer 2

Attributes

Question 3

Each attribute has a _____ (or data type) associated with it

Answer 3

value set

Question 4

Types of Attributes

Answer 4

Single
Composite
Multi-valued

Question 5

Entities with the same basic attributes are grouped or typed into an ________

Answer 5

entity type

Question 6

An attribute of an entity type for which each entity must have a unique value is called a ________ of the entity type.

Answer 6

key attribute

Question 7

Each key is _____

Answer 7

underlined

Question 8

Each entity type will have a collection of entities stored in the database called the

Answer 8

entity set or sometimes entity collection

Question 9

Each simple attribute is associated with a _______

Answer 9

value set

Question 10

specifies the set of values associated with an attribute

Answer 10

value set

Question 11

A ________relates two or more distinct entities with a specific meaning.

Answer 11

relationship

Question 12

Relationships of the same type are grouped or typed into a _______-

Answer 12

relationship type

Question 13

The degree of a relationship type is the number of _________

Answer 13

participating entity types

Question 14

Is the schema description of a relationship, identifies relationship name and participating entity types, and certain relationship constraints

Answer 14

relationship type

Question 15

The current set of relationship instances represented in the database, the current state of a relationship type

Answer 15

Relationship Set

Question 16

Constraints on Relationship Types also known as

Answer 16

ratio constraints

Question 17

specifies maximum participation

Answer 17

Cardinality Ratio

Question 18

specifies minimum participation

Answer 18

Existence Dependency Constraint

Question 19

Existence Dependency Constraint also known as

Answer 19

participation constraint

Question 20

A relationship type between the same participating entity type in distinct roles

Answer 20

Recursive Relationship Type

Question 21

Recursive Relationship Type also called

Answer 21

self-referencing relationship type

Question 22

An entity that does not have a key attribute and that is identification-dependent on another entity type

Answer 22

weak entity type

Question 23

A weak entity must participate in an ________ with an owner or identifying entity type

Answer 23

identifying relationship type