A data analyst is preparing a dataset for analysis and notices that the `age` column contains some values like 'N/A', 'unknown', and '999'. The analyst wants to ensure the data is clean and usable. What is the most appropriate cleansing step?

Replace all non-numeric values with the average age

Replace 'N/A' and 'unknown' with NULL and treat '999' as an outlier to be reviewed or removed

Leave the data as is because the analysis tool will handle it

Delete all rows that contain any non-numeric value

A data analyst is merging two datasets with a `country` field. Dataset 1 uses 'USA', 'UK', and 'UAE'. Dataset 2 uses 'United States', 'United Kingdom', and 'United Arab Emirates'. The analyst needs to create a unified dataset. What is the most appropriate transformation?

Delete the country field from one dataset

Create a mapping table that translates the abbreviations to full names and apply it to Dataset 1

Use a fuzzy matching algorithm to guess the correct matches

Keep the values as they are and use a case-insensitive join

A marketing analyst wants to enrich customer profiles with social media engagement metrics. The social media platform provides an API that requires an API key and returns data in JSON format. The analyst's current customer data is stored in a SQL database. What is the most efficient way to combine the social media data with the existing customer data?

Manually copy the social media data from the API documentation into the SQL database

Use the API to fetch the social media data and then join it with the SQL data using a common identifier like customer ID

Export the SQL database to a CSV file and upload it to the social media platform

Use a screen scraper to extract data from the social media website's HTML pages

What is the primary purpose of the Load step in an ETL process?

To read data from source systems

To write the processed data into the target system

CompTIAData+

Domain 2Objective 1

Use Data Acquisition Methods DA0-001 Practice Questions (Page 6)

Part of the Data acquisition and preparation domain, which accounts for 22% of the DA0-001 exam. CompTIA does not publish an official question count, but from its 90-minute exam (~35–60 total, ~8–13 in this domain), expect 3–4 from this objective — we provide 35 practice questions to prepare you well beyond it. (estimate)

35questions here

7free pages

10concepts

22%of the exam

Questions 26–30

26foundation · easy
Which SQL clause is used to filter rows based on a condition before grouping them?
Select an answer first
27application · medium
A data analyst is preparing a dataset for analysis and notices that the `age` column contains some values like 'N/A', 'unknown', and '999'. The analyst wants to ensure the data is clean and usable. What is the most appropriate cleansing step?
Select an answer first
28expert · hard
A data analyst is merging two datasets with a `country` field. Dataset 1 uses 'USA', 'UK', and 'UAE'. Dataset 2 uses 'United States', 'United Kingdom', and 'United Arab Emirates'. The analyst needs to create a unified dataset. What is the most appropriate transformation?
Select an answer first
29application · medium
A marketing analyst wants to enrich customer profiles with social media engagement metrics. The social media platform provides an API that requires an API key and returns data in JSON format. The analyst's current customer data is stored in a SQL database. What is the most efficient way to combine the social media data with the existing customer data?
Select an answer first
30foundation · easy
What is the primary purpose of the Load step in an ETL process?
Select an answer first

Finished these 5 questions?

Review the revealed explanations, or continue through the curriculum.

Next 5 questions →Back to DA0-001

Free Basic Practice is a study aid with revealable answers — not a scored exam. Examers.io is independent and not affiliated with or endorsed by CompTIA. “DA0-001” is a trademark of its owner, used for identification only.

Use Data Acquisition Methods DA0-001 Practice Questions (Page 6)

Questions 26–30

Which SQL clause is used to filter rows based on a condition before grouping them?

A data analyst is preparing a dataset for analysis and notices that the `age` column contains some values like 'N/A', 'unknown', and '999'. The analyst wants to ensure the data is clean and usable. What is the most appropriate cleansing step?

A data analyst is merging two datasets with a `country` field. Dataset 1 uses 'USA', 'UK', and 'UAE'. Dataset 2 uses 'United States', 'United Kingdom', and 'United Arab Emirates'. The analyst needs to create a unified dataset. What is the most appropriate transformation?

What is the primary purpose of the Load step in an ETL process?

Keep studying — Data acquisition and preparation