w12d1

Question 1

Databases are designed to suppor

Answer 1

day to day activities

Question 2

Relational databases help to support

Answer 2

data integrity
data sharability
data availability
data evolvability
avoiding redundency

Question 3

Relational databases are composed of

Answer 3

tables of attributes

relationships

Question 4

Temporal Data

If you keep track of everything

Answer 4

You might have a lot of old data that is not needed

• to support day to day organizations
• especially in large organizations

Question 5

seperate history files and current data files might keep

and are less efficient for _____

Answer 5

a lot of old data that is seldom needed

dealing with temporal data

Question 6

analyzing historical data can be useful for

Answer 6

planning for the future

Question 7

Historic data is limited to
contains
is not relevant to 
should be separated from relevant data to
is the focus of 
And might be dealt with by

Answer 7

the past
facts
day to day activities
improve processing efficiency
ISO/IEC 13249-7
A database management system

Question 8

Temporal data contains
is needed for
Should not be separated from
Is not dealt with by an

Answer 8

past, present and future ….. facts plans and other data
day to day activities
other current data
ISO standard - so is the responsiblity

Question 9

Data warehouses can help

In a separate system that

Answer 9

• meet the needs of analyzing historic data

- Avoids degrading the performance of the OLTP database and better supports analyzing the data

Question 10

Data warehousing is

Answer 10

A subject-oriented, integrated, time-varient, and non-volatile collection of data in support of managements decision making process

Question 11

Databases support

Answer 11

day to day transaction processing (Online transaction processing)

Question 12

providing suitable performance

Answer 12

databases should not be slowed down,

Handling major analysis of exisitng data by techniques such as OLAP, data mining

Question 13

Olap processing requires

Answer 13

Seperate resources

• storage of a copy of the data
• processing that can handle large

Question 14

OLAP

Answer 14

Temporal data that may not be required by OLTP

Question 15

Data warehouses are developed to

Answer 15

support olap, data mining and related processing

Question 16

Data warehousing fundamentals

Answer 16

integrated by subject (topic of interest to organization)

 - organization level integration
 - may involve some gaps to put it together

Temporal and non-volatile

 - keep track of all versions of data
       - the periods for which they were valid

Data in a data warehouse
- is not added to or changed

Structure for ease of analysis
- store results of as many joins as possible