Week 3: Databases: Where data lives
1. Primary and foreign keys are two connected identifiers within separate tables. These tables exist in what kind of database?
- Metadata
- Primary
- Relational
- Normalized
2. When working with data from an external source, what can metadata help data analysts do? Select all that apply.
- Ensure data is clean and reliable
- Combine data from more than one source
- Understand the contents of a database
- Choose which analyses to run
3.Think about data as a student at a high school. In this metaphor, which of the following are examples of metadata? Select all that apply.
- Student’s ID number
- Student’s enrollment date
- Classes the student is enrolled in
- Grades the student earns
4. Fill in the blank: Data _____ is the process of ensuring the formal management of a company’s data assets.
- aggregation
- integrity
- mapping
- governance
5. In what circumstance might a data analyst choose not to use external data in their analysis?
- The data represents diverse perspectives
- The data is too thorough
- The data is free for anyone to access
- The data cannot be confirmed to be reliable
6. A nonprofit maintains a list of how many laptops they provide to each school in the county. In the table, there is a column called number_of_laptops. A data analyst wants to determine which schools were given the fewest laptops. How should they sort the data to return these schools first?
- Sort alphabetically in ascending order
- Sort numerically in descending order
- Sort alphabetically in descending order
- Sort numerically in ascending order
7.When writing a query, it's necessary for the name of the dataset to be inside two backticks in order for the query to run properly.
- True
- False
8. You are working with a database table that contains customer data. The city column lists the city where each customer is located. You want to find out which customers are located in Berlin.
You write the SQL query below. Add a WHERE clause that will return only customers located in Berlin.
How many customers are located in Berlin?
- 9
- 12
- 2
- 7
9. Relational databases contain a series of tables connected to form relationships. Which two types of fields exist in two connected tables?
- Star and snowflake schemas
- Descriptive and structural metadata
- Internal and external data
- Primary and foreign keys
10. Data analysts use metadata for what tasks? Select all that apply.
- To combine data from more than one source
- To perform data analyses
- To interpret the contents of a database
- To evaluate the quality of data
11. Think about data as driving a taxi cab. In this metaphor, which of the following are examples of metadata? Select all that apply.
- Company that owns the taxi
- License plate number
- Make and model of the taxi cab
- Passengers the taxi picks up
12. Fill in the blank: Data governance is the process of ensuring that a company’s _____ are managed in a formal manner.
- business tasks
- data engineers
- data assets
- business strategies
13. What are some key benefits of using external data? Select all that apply.
- External data is always reliable.
- External data is free to use.
- External data has broad reach.
- External data can provide industry-level perspectives.
14. A data analyst reviews a national database of movie theater showings. They want to find the first movies shown in San Francisco in 2001. How can they organize the data to return the first 10 movies shown at the top of their list? Select all that apply.
- Filter out showings not in 2001
- Sort by date in descending order
- Sort by date in ascending order
- Filter out showings outside of San Francisco
15. You are working with a database table that contains customer data. The state column lists the state where each customer is located. The state names are abbreviated. You want to find out which customers are located in the state of Florida (FL).
You write the SQL query below. Add a WHERE clause that will return only customers located in FL.
How many customers are located in FL?
- 6
- 4
- 1
- 3
16. Structural metadata indicates how a piece of data is organized and whether it’s part of one or more than one data collection.
- True
- False
17. Relational databases illustrate relationships between tables. Which fields represent the connection between these tables? Select all that apply.
- Foreign keys
- External keys
- Primary keys
- Secondary keys
18. When writing a query, you must remove the two backticks around the name of the dataset in order for the query to run properly.
- True
- False
19. You are working with a database table that contains customer data. The first_name column lists the first name of each customer. You are only interested in customers with the first name Mark.
You write the SQL query below. Add a WHERE clause that will return only customers named Mark.
How many customers are named Mark?
- 1
- 5
- 3
- 2
20. Metadata is data about data. What kinds of information can metadata offer about a particular dataset? Select all that apply.
- How to combine the data with another dataset
- Which analyses to perform on the data
- If the data is clean and reliable
- What kinds of data it contains
21. A data analyst reviews a database of Wisconsin car sales to find the last car models sold in Milwaukee in 2019. How can they sort and filter the data to return the last five cars sold at the top of their list? Select all that apply.
- Filter out sales outside of Milwaukee
- Filter out sales not in 2019
- Sort by sale date in descending order
- Sort by sale date in ascending order
22. When writing a query, the name of the dataset can either be inside two backticks, or not, and the query will still run properly.
- True
- False
23. A data analyst chooses not to use external data because it represents diverse perspectives. This is an appropriate decision when working with external data.
- True
- False