ch2

Question 1

data integrity

Answer 1

ensure accuracy and precision in data

Question 2

ER model

Answer 2

detailed, logical representation of data. Parts: entities, relationships, and attributes

Question 3

relationship “grammar” model

Question 4

read maximum cardinality on diagram

Answer 4

go to other side of line. max is always one closest to the other entity (think many)

Question 5

what data modeling is all about

Answer 5

documenting rules and policies of organization

Question 6

business rule

Answer 6

statement that defines of constrains some aspect of the business

Question 7

rules identified by

Answer 7

ask who what when where why how

Question 8

term

Answer 8

word that has a specific meaning for the business. example: course

Question 9

fact

Answer 9

association between two or more terms. documented as simple

Question 10

entity

Answer 10

a noun that organization wants to keep data for

Question 11

entity type

Answer 11

collection of entities that share common attributes

Question 12

entity instance

Answer 12

single occurance of an entity type

Question 13

strong entity type

Answer 13

independent of other entity types

Question 14

weak entity type

Answer 14

existance depends on some other entity type. if owner is deleted, weak also gets deleted

Question 15

attribute

Answer 15

property or characteristic that is of interest

Question 16

required attribute

Answer 16

must be present in each entity instance. often time symbolized by * or boldface

Question 17

composite attribute

Answer 17

has composite/separate parts. often parts marked in parentheses

Question 18

simple (atomic) attributes

Answer 18

does NOT have composite parts

Question 19

mutivalued attribute

Answer 19

field that will have more than one value for each instance. often marked in brackets

Question 20

derived attribute

Answer 20

values calculated from other values. like age from date. sometimes signified by ‘/’

Question 21

identifier

Answer 21

unique attribute like ID for each instance. should not have to change

Question 22

relationship

Answer 22

any association of an interaction between two or more entity types. represent business rules

Question 23

relationship type

Answer 23

meaningful association between entity types

Question 24

relationship instance

Answer 24

meaningful association between entity instances. only one of each entity allowed

Question 25

relationship attribute

Answer 25

attribute that on on the relationship, not the two associated entities. “step away from one to many relationships”

Question 26

associative entity

Answer 26

associate the instances of one or more entity types. look for many to many cardinality. MARKED BY CURVED RECTANGLE

Question 27

degree of relationship

Answer 27

number of entitys that participate in the relationship

Question 28

unary relationship

Answer 28

relationship between instances of ONE entity type

Question 29

binary relationship

Answer 29

relationship between instances of two entity types

Question 30

tertiary relationship

Answer 30

simultaneous relationship amoung instances of three entity types

Question 31

cardinality constraint

Answer 31

rule that specifies number of instances that can have a relationship with another entity

Question 32

maximum cardinality

Answer 32

maximum number of instances of B that can be associated with A

Question 33

mandatory one

Answer 33

min and max are both ONE

Question 34

HIPAA

Answer 34

healthcare record privacy act

Question 35

time stamp

Answer 35

time associated with data