Module 3: Database Essentials Answers (Part 2: Q16–30)
This is Part 2 of the Module 3 quiz answers for “Database Essentials” from the Google Data Analytics Professional Certificate on Coursera.
Here, we’ll walk through questions 16 to 30 with detailed explanations to support your learning.
To find answers to the remaining questions, check out the full module breakdown below:
16. Which cases are most often used for column names in a database table, and represent a best practice? Select all that apply.
- Sentence case
- Lower case ✅
- Camel case ✅
- Snake case ✅
Explanation:
Lowercase, camel case (e.g., columnName), and snake case (e.g., column_name) are commonly used for column names in database tables. These cases enhance consistency and readability. Sentence case is not a common practice for column naming.
17. In BigQuery, what optional syntax can be removed from the following FROM clause without stopping the query from running?
FROM `bigquery-public-data.sunroof_solar.solar_potential_by_postal_code`
- Dashes
- Backticks ✅
- Dots
- Underscores
Explanation:
In BigQuery, backticks are optional unless there are special characters, spaces, or reserved words in the table name. Removing backticks in this example does not stop the query from running.
18. In the following FROM clause, what is the table name in the SQL query?
FROM bigquery-public-data.sunroof_solar.solar_potential_by_postal_code
- sunroof_solar
- solar_potential_by_postal_code ✅
- solar.solar
- public-data.sunroof
Explanation: The full structure represents the project, dataset, and table. Here:
- bigquery-public-data is the project name.
- sunroof_solar is the dataset name.
- solar_potential_by_postal_code is the table name.
*Module 3 challenge*
Graded Quiz.
19. Primary and foreign keys are two connected identifiers within separate tables. These tables exist in what kind of database?
- Metadata
- Primary
- Relational ✅
- Normalized
Explanation:
Relational databases store data in related tables, with primary keys uniquely identifying records and foreign keys linking them.
20. 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
Explanation:
Metadata gives context about data quality, meaning, and structure—critical for combining and trusting data.
21.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
Explanation:
All of these describe or provide context about the student (data), which is exactly what metadata does.
22. Fill in the blank: Data _____ is the process of ensuring the formal management of a company’s data assets.
- aggregation
- integrity
- mapping
- governance ✅
Explanation:
Data governance refers to the formal management process of ensuring data integrity, privacy, security, and accessibility within an organization.
23. 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 ✅
Explanation:
If external data is not reliable or cannot be validated, a data analyst may choose not to use it to avoid errors or misleading insights.
24. 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 ✅
Explanation:
Sorting in ascending order shows the smallest numbers first, revealing schools with the fewest laptops.
25. 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 ✅
Explanation:
Backticks are optional unless using reserved words or special characters. Most dataset names run fine without them.
26. 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
Explanation:
Using a WHERE city = 'Berlin' clause filters the table to show only Berlin-based customers—2 in this case.
27. 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 ✅
Explanation:
Primary keys identify records in one table, while foreign keys link to those records from another table.
28. 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 ✅
Explanation:
Metadata provides information about the structure, content, and quality of data, allowing data analysts to interpret, combine, and evaluate it from various sources.
29. 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
Explanation:
These details describe the taxi, just like metadata describes or gives context to data.
30. 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
Explanation:
Data assets are valuable resources that need structured oversight, which is what data governance ensures.
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