Module 3: Database essentials

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In this post, I provide accurate answers and detailed explanations for Module 3: Database essentials of Course 3: Prepare Data for Exploration – Google Data Analytics Professional Certificate.

Whether you’re preparing for quizzes or brushing up on your knowledge, these insights will help you master the concepts effectively. Let’s dive into the correct answers and detailed explanations for each question.

Here, we’ll walk through questions 1 to 15 with detailed explanations to support your learning.

To find answers to the remaining questions, check out the full module breakdown below:

Test your knowledge on working with databases

Practice Quiz

1. Fill in the blank: A _____ is an identifier that references a database column in which each value is unique.

  • relation
  • field
  • foreign key
  • primary key ✅

Explanation:
A primary key uniquely identifies each record in a database table. It ensures that no two rows have the same key value, allowing for precise data referencing.

2. Fill in the blank: A relational database contains a series of _____ that can be connected to form relationships.

  • fields
  • cells
  • spreadsheets
  • tables ✅

Explanation:
In a relational database, data is organized into tables, and these tables are related to each other using keys (primary and foreign). This structure enables efficient data organization and querying.

3. A key benefit of working with normalized databases is that they help lower data redundancy. Which of the following is an example of redundancy?

  • A database containing two foreign keys
  • A database that forms two or more relationships
  • The same piece of data being stored in two different places ✅
  • Team members in different office locations working with the same data

Explanation:
Redundancy occurs when identical data is stored in multiple locations within a database. This can lead to inconsistencies and increased storage requirements, which normalization aims to prevent.

Test your knowledge on metadata

Practice Quiz

4. A large company has several data collections across its many departments. What kind of metadata indicates exactly how many collections a piece of data lives in?

  • Structural ✅
  • Administrative
  • Descriptive
  • Representative

Explanation:
Structural metadata provides information about how data is organized and stored, such as the number of collections it exists in, its format, and its relationships with other data.

5. The date and time a photo was taken is an example of which kind of metadata?

  • Descriptive
  • Structural
  • Representative
  • Administrative ✅

Explanation:
Administrative metadata includes information about the creation, management, and preservation of data, such as the date and time a photo was taken or its file type.

6. A large metropolitan high school gives each of its students an ID number to differentiate them in its database. What kind of metadata are the ID numbers?

  • Descriptive ✅
  • Administrative
  • Representative
  • Structural

Explanation:
Descriptive metadata is used to describe or identify data. In this case, the student ID numbers serve as identifiers, making them a type of descriptive metadata.

7. A company needs to merge third-party data with its own data. Which of the following actions will help make this process successful? Select all that apply.

  • Use the metadata to evaluate the third-party data’s quality and credibility. ✅
  • Use the metadata to standardize the data. ✅
  • Alter the company’s metadata to more closely reflect the incoming metadata.
  • Replace the incoming data’s metadata with its own company metadata.

Explanation:

  • Metadata can provide insights into the quality, source, and credibility of third-party data, which is crucial before integration.
  • Standardizing metadata ensures consistency and compatibility between the company’s data and the third-party data.
  • Altering or replacing metadata without careful consideration can lead to loss of important context and decrease data reliability.

Test your knowledge on accessing data sources

Practice Quiz

8. A CSV file saves data in a table format. What does CSV stand for?

  • Comma-separated values ✅
  • Compatible scientific variables
  • Cell-structured variables
  • Calculated spreadsheet values

Explanation:
CSV stands for comma-separated values, a file format where data is saved in plain text, with values separated by commas to represent a table structure.

9. A data analyst wants to bring data from a CSV file into a spreadsheet. This is an example of what process?

  • Normalizing data
  • Filing data
  • Importing data ✅
  • Editing data

Explanation:
Importing data involves transferring data from one format or file (like a CSV file) into another, such as a spreadsheet.

10. A CSV file makes it easier for data analysts to complete which tasks? Select all that apply.

  • Manage multiple tabs within a worksheet
  • Import data to a new spreadsheet ✅
  • Distinguish values from one another ✅
  • Examine a small subset of a large dataset ✅

Explanation:

  • Import data to a new spreadsheet: CSV files are widely compatible and can be easily imported into spreadsheet software.
  • Distinguish values from one another: Commas in a CSV file separate data into distinct fields, making it easy to identify individual values.
  • Examine a small subset of a large dataset: Analysts can save or extract smaller, manageable portions of a large dataset in CSV format for focused analysis.

Note: CSV files do not support managing multiple tabs within a worksheet, as they are limited to single-sheet data.

Test your knowledge on sorting and filtering

Practice Quiz

11. What is the process for arranging data into a meaningful order to make it easier to understand, analyze, and visualize?

  • Filtering
  • Prioritizing
  • Reframing
  • Sorting ✅

Explanation:
Sorting organizes data in a specific order, such as ascending or descending, to make patterns and trends more evident for analysis and visualization.

12. A data analyst is reviewing a national database of real estate sales. They are only interested in sales of condominiums. How can the analyst narrow their scope?

  • Sort by condominium sales
  • Sort by non-condominium sales
  • Filter out condominium sales
  • Filter out non-condominium sales ✅

Explanation:
Filtering out non-condominium sales removes unnecessary data, leaving only the records of interest, i.e., condominium sales.

13. A data analyst works for a rental car company. They have a spreadsheet that lists car ID numbers and the dates cars were returned. How can they sort the spreadsheet to find the most recently returned cars?

  • By return date, in descending order ✅
  • By car numerical ID, in descending order
  • By return date, in ascending order
  • By car numerical ID, in ascending order

Explanation:
Sorting by return date in descending order places the most recent dates at the top of the list, making it easy to identify the latest returned cars.

14. Fill in the blank: To keep a header row at the top of a spreadsheet, highlight the row and select _____ from the View menu.

  • Pin
  • Freeze ✅
  • Lock
  • Set

Explanation:
The Freeze option allows you to lock the header row at the top of the spreadsheet, so it remains visible while scrolling through the data.

Test your knowledge on using SQL with large datasets

Practice Quiz

15. In MySQL, what is acceptable syntax for the SELECT keyword? Select all that apply.

  • select ✅
  • ‘SELECT’
  • SELECT ✅
  • “SELECT”

Explanation:
In MySQL, the SELECT keyword is case-insensitive, so both SELECT and select are valid. However, enclosing SELECT in single (”) or double (“”) quotes turns it into a string literal, which causes an error. Therefore, SELECT and select (without quotes) are the correct syntaxes.

That’s it for Part 1! Continue your learning journey with the next set of answers.

Next Part: Module 3: Database Essentials Answers (Part 2: Q16–30)

Part 2: Q16–30

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