Introduction to Data and Databases

Which of these statements about gathering data using a focus group is false?

Focus groups are a good method of reaching a large number of respondents

What type of join includes all data from both original tables, creating null values where necessary?

Full outer join

Why can unstructured data be challenging to analyze?

It can't be easily categorized

Which of these is the most common type of relationship in most databases?

One-to-Many

In a database table, a single column with a unique value for each record has what name?

Primary key

Which of these is most likely to be the name of a fact table?

Purchases

Which of these statements about databases is false?

All the data in a database is stored in tables

Which of these cleaning tasks would involve adding more columns to your data?

Splitting an address column into street, city, state and country

What is a Boolean data type used for?

Storing true or false values

Which of these is a data type commonly used for text data?

String

Which of these is most likely to be an external data source?

The International Monetary Fund (IMF)

How can companies use APIs in data analysis?

To connect to software from other companies

Which of the following best describes structured data?

A table of sales figures

Which of these is an example of gathering data through an experiment?

A website creates two versions of a page and compares how people use both pages

Of these survey questions, which is most likely to have a response made up of unstructured data?

Do you have any other suggestions?

What does a primary key in a database table do?

Uniquely identifies each record

Which layout is described as 'short and fat'?

Data with many columns and few rows

What is the precision of the number 246.01?

5

Which of these is an example of structured data?

A Database of Sales Transactions

Which of these describes a star schema database layout?

A central fact table is linked to several surrounding dimension tables

Which type is used for text data in databases?

Character/String

In a database table, what name is used when a combination of multiple fields provides a unique value for each record?

Compound Key

You are joining a sales table (on the left) to a product table (on the right). Product ID is the column that links both tables. What join type will create a table that contains only Product IDs which feature in both tables?

Inner Join

Which of these statements is true for a pivoted data set?

It has more columns than it would in an unpivoted format

What is the final step before starting an analytics project?

Shaping data into the right format