Ch2

Question 1

Business rules

Answer 1

• statements that define or contrain
• give businesss structure
• derived from policies/prcodeus
• are automated through dbms and known by end users

Question 2

4 categories of busienss rules

Answer 2

1. terms: these are entities (term is defined as…)
2. facts: relationships in an erd, attributed in an erd, or a generalization structure
3. constraints: prevent an action from taking place
4. derivations: define how knowledge in one form can be transformed into knowledgein another form

Question 3

characterisitcs of good business rules

Answer 3

declarative, precise, atomic, consistent, expressible, distinct, business oriented

Question 4

entity legend:
strong
weak a
associative
(Entity types)

Answer 4

rectangle

double rectangle

rounded corners

Question 5

entity legend attributes

IDENTIFIER
PARTIAL IDENTIIFER
optional
[Derived]
{mv}
compo(os,it,e)

Answer 5

underline

double underline

derived from metadata

skills

several parts

Question 6

what is an entity

Answer 6

person place object event or concept

Question 7

entity type

Answer 7

cllection of entities that share common property

(Strong,weak,…)

Question 8

enetitiy instancen

Answer 8

one occurence of an entity type (so one data row)

Question 9

are reports entities?

Answer 9

no

Question 10

attributre

Answer 10

property or characteiristc of an entity or relationship typecl

Question 11

classifications of attributes

Answer 11

required v optional

simple v comp

single value v multiv

stored v derived

identifer

Question 12

associative entity? two types

Answer 12

1. attribute on a relationship (like the recntagle box coming off a dashed line)
2. assciiative entity (a rounded edges square b/w 2 m:m)

Question 13

does weak ent have unique ID

Answer 13

no only a partial!

Question 14

A value that indicates the date or time of a data value is called a:

Answer 14

timestamp

Question 15

In the following diagram, which is true? item/bom structrure

Answer 15

many to many!!!

Question 15

An entity type name should be all of the following EXCEPT:

Answer 15

AS SHORT AS POSSIBLE

Question 16

In an E-R diagram, there are/is ________ business rule(s) for every relationship.

Answer 16

TWO

Question 17

A good data definition will describe all of the characteristics of a data object EXCEPT:

Answer 17

who can delete data

Question 18

fact is an association between 2+ terms

Answer 18

TRMSMMSSMMS

Question 19

The number of entity types that participate in a relationship is called the:

Answer 19

DEGREEEEEEEEEE

Question 20

The most common types of entities are:

Answer 20

STRONG

Question 21

which of the following is NOT a agood characterisitc of a data name

RELATES TO TECHNICAL CHARACTERISTIC OF THE SYSTEMRELATES TO TECHNICAL CHARACTERISTIC OF THE SYSTEMRELATES TO TECHNICAL CHARACTERISTIC OF THE SYSTEMRELATES TO TECHNICAL CHARACTERISTIC OF THE SYSTEMRELATES TO TECHNICAL CHARACTERISTIC OF THE SYSTEMRELATES TO TECHNICAL CHARACTERISTIC OF THE SYSTEMRELATES TO TECHNICAL CHARACTERISTIC OF THE SYSTEMRELATES TO TECHNICAL CHARACTERISTIC OF THE SYSTEM

Answer 21

RELATES TO TECHNICAL CHARACTERISTIC OF THE SYSTEM

Question 22

WHy data modeling important?

data characterisics are important

Question 23

data def does not say whp can delete data!!