Week 5

Question 1

What is a data model?

Answer 1

A simple representation of complex, real world data strcutures
-> the semiformal format allows for precise but understandable format

Question 2

What are the uses of a data model?

Answer 2

1. Can be used by IT to model a database

2. Can be used by business to understand a database

Question 3

What is the entity relationship model?

Answer 3

A graphical representation of entities and their relationoships in a database structure

Question 4

What are the components of a relationship model?

Answer 4

Entity: Anything about which data are to be collected and stored

Attribute: A characteristic of an attribute

Relationship: Describes the association among entities

Constraint: A restriction placed on the data (often business rules)

Question 5

What kind of relationships are possible in an entity relationship model?

Answer 5

One to many: (1:M)
Many to many (M:N or M:M)
One to one (1:1)

Question 6

What is a business rule?

Answer 6

Internal policies. An example can be: the store can only be managed by one employee at the time

Question 7

What is the crowsfeet notation of an ER model?

Answer 7

It uses the graphic representation of a database.
So every entity is in a table with rows for all the attributes. Additionally, the first attribute is the key attribute and the relationsship arrows look like crows feet indicating the relationship type

Question 8

What are the 5 V’s of Big Data?

Answer 8

• Volume
• Variety
• Velocity
• Value
• Veracity

Question 9

What is meant by volume in big data?

Answer 9

The data comes in large quantities

Question 10

What is meant by variety in big data?

Answer 10

There is lots of different data that is collected. This also includes unstructured data such as photos.

Question 11

What is meant by velocity in big data?

Answer 11

The high speed at which data is created.

Question 12

What is meant by value in big data?

Answer 12

Commercial and strategic data that can lead to competitive advantage for companies

Question 13

What is meany by veracity in big data?

Answer 13

Is all data true? Think about customer reviews that can be false or fabricated.

Question 14

What are those 5V’s in relation to businesses?

Answer 14

Can be seen as challenges but also opportunities.

Question 15

What kind of degree can there be in relationships in a ER model?

Answer 15

• Unary -> relationship related to one entity
• Binary -> relationship between two entities
• Ternary -> relationship between three entities