Part 4 - A World Built of Data

Question 1

What is SEO? Why is it important?

Answer 1

Search Engine Optimisation - used to make your website appear higher up the list when people search it in google. The higher links get the most traffic with the top link getting over 30% of all users.

Question 2

What is SQL? What is it used for?

Answer 2

Structured Query Language is a text based code which allows you to search databases.

Question 3

What is Cashing?

Answer 3

Many pages on the internet are stored in databases and pulled up when a user runs a query (knowingly or unknowingly). Cashing is where the page stores popular queries as a page to save repeatedly running the same queries.

Question 4

What is the difference between a database and a spreadsheet?

Answer 4

Databases are meant for storing and querying large amounts of data.

While there is some cross over in functionality, spreadsheets are designed for handling numeric data (such as company accounts) and to make calculations or manipulations on lesser amounts of data

Question 5

What is an issue with storing data in a flat database?

Answer 5

If a key value is changed then every record holding this value must be manually changed. E.g. if the date of an occasion is adjusted then each persons calendar appointment would have to be adjusted manually in the database

Question 6

What are Entities and Attributes?

Answer 6

Entities are a “thing” which can be entered into relational databases. Tangible entities such as a person or intangible entities such as a course or an invitation can be within fields of a database. Attributes are fields under the entity so attributes for a person might be height, weight and age. Each person has the same attributes in the database but with different values

Question 7

What are the benefits of a relational database and normalisation?

Answer 7

If a student is on multiple courses then you don’t have to have separate records or fields for each attribute with empty fields in some areas.

If there is an administrative change then you can make the change without having to find every occurrence in the database

Question 8

What is sampling?

Answer 8

A method for drawing conclusions from a small cross section of data to avoid having to examine the entire data set

Question 9

How is Big Data defines?

Answer 9

Using the 3 Vs -
Volume: large amounts of data needs to be processed
Velocity: there is a relentless demand for data to be processed at an increasing pace
Variety: the data being acquired can take any form - not only numeric or text but video or audio
Veracity: ensuring correctness and trustworthiness of the data