CH 3 Final

Question 1

Different ways to store data:

Answer 1

falt files and databases

Question 2

flat files:

Answer 2

data is stored in one giant table. typically different functions have separate flat files that do not link to each other.

ex. excel

Question 3

databases

Answer 3

data is shared between functions.

Question 4

three types of databases:

Answer 4

hierarchical, networks and relational

Question 5

Three anomalies:

Answer 5

insert, delete, update

Question 6

data modeling:

Answer 6

process of defining a database so that it faithfully represents all aspects of the organization. the end result is a third normal form (3NF) database

Question 7

databases are comprised of the following:

Answer 7

entities, attributes, records

Question 8

entities

Answer 8

anything about which the organization wishes to store data.

i.e. employees, sales, payroll

entity info is stored in a table.

Question 9

attributes

Answer 9

aka fields.
what you want to know about the entity.

columns in a table.
birthday of employee or SSN

Question 10

records:

Answer 10

the individual instances in a table. stored in rows.

record = row

Question 11

record keys:

Answer 11

primary keys and foreign keys

Question 12

primary key:

Answer 12

i.e. customer #, invoice #, employee #, CWID

Primary key must be unique

Question 13

foreign keys:

Answer 13

used to link tables.

primary keys from other tables.

Question 14

REA meaning:

Answer 14

resource, event, agent.

Question 15

resources:

Answer 15

things of value an organization acquires and uses (e.g. cash, inventory, equipment)

Question 16

events:

Answer 16

business activities (e.g. sales order, sales event)

Question 17

agents:

Answer 17

people and organizations (e.g. employees, customers, vendors)

Question 18

when creating an ERD you should do what?

Answer 18

identify the events.
identify the resources and agents.
determine the linkages between entities.
determine the cardinalities.

Question 19

o

|

Answer 19

zero
one
many

Question 20

one to one is labeled as

Answer 20

1:1

Question 21

one to many is labels as

Answer 21

1:N

Question 22

Many to many is labeled as

Answer 22

M:N

Question 23

When designing a database you should?

Answer 23

1. create a table for each entity and for each many to many relationship.
2. identify attributes, including primary keys.
3. Assign foreign keys for each relationship that is not many to many.

Question 24

when assigning foreign keys, remember

Answer 24

many to many relationships have no foreign keys.

for one to one and one to many relationships, put the foreign key where it will always be single-valued.

Question 25

database administrator:

Answer 25

person responsible for maintaining the database.

Question 26

data dictionary

Answer 26

describes each field in the database.

Question 27

data integrity controls:

Answer 27

ensure accuracy of data

Question 28

types of integrity data controls:

Answer 28

transaction controls and concurrency controls

Question 29

transaction controls:

Answer 29

type of data integrity control that ensures transactions are performed accurately

Question 30

concurrency controls:

Answer 30

type of data integrity controls that prevent simultaneous access to a table by multiple users and ensure that transactions are performed sequentially.