The answer is to use Column Masking, Column Hashing, and Column Delete transformations. These three actions are the built-in DataBrew PII masking transformations that directly address the need to obscure or remove personally identifiable information from datasets. Column Masking replaces sensitive values with a fixed pattern like 'XXXX', Column Hashing applies a cryptographic hash to irreversibly transform the data, and Column Delete removes the column entirely, effectively masking the PII by eliminating it. On the AWS Certified Data Engineer Associate DEA-C01 exam, this question tests your knowledge of DataBrew’s native transformation catalog versus external security services; a common trap is confusing encryption or tokenization—which are not available as one-click DataBrew steps—with these three valid options. Remember that DataBrew handles masking at the column level, not through key management or custom logic. A helpful memory tip is the three D’s: Delete, Disguise (mask), and Digest (hash).
DEA-C01 Data Operations and Support Practice Question
This DEA-C01 practice question tests your understanding of data operations and support. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A company is using AWS Glue DataBrew to clean and transform data from an S3 bucket. The data contains personally identifiable information (PII). The company wants to mask the PII columns before making the dataset available to analysts. Which THREE actions can the engineer perform using DataBrew to mask PII? (Choose THREE.)
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Apply a 'Column masking' transformation to replace values with 'XXX'.
Options A, C, and D are correct. DataBrew provides built-in transformations for masking: 'Column masking' replaces values with a fixed pattern, 'Column hashing' replaces with a hash, and 'Column delete' removes the column. Option B is wrong because 'Column encryption' is not a DataBrew transformation; encryption is typically done at rest or with KMS. Option E is wrong because there is no 'Column tokenization' transformation in DataBrew; tokenization would require a custom recipe step.
Key principle: Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✓
Apply a 'Column masking' transformation to replace values with 'XXX'.
Why this is correct
Column masking is a built-in transformation that hides data.
Apply a 'Column encryption' transformation to encrypt the column values.
Why it's wrong here
DataBrew does not have a column encryption transformation; encryption is done at the storage level.
Common exam traps
Common exam trap: usable hosts are not the same as total addresses
Subnetting questions often tempt you into counting all addresses. In normal IPv4 subnets, the network and broadcast addresses are not usable host addresses.
Detailed technical explanation
How to think about this question
Subnetting questions test whether you can identify the network, broadcast address, usable range, mask and correct subnet. Slow down enough to calculate the block size correctly.
KKey Concepts to Remember
CIDR notation defines the prefix length.
Block size helps identify subnet boundaries.
Network and broadcast addresses are not usable hosts in normal IPv4 subnets.
The required host count determines the smallest suitable subnet.
TExam Day Tips
→Write the block size before choosing the subnet.
→Check whether the question asks for hosts, subnets or a specific address range.
→Do not confuse /24, /25, /26 and /27 host counts.
Key takeaway
Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.
Real-world example
How this comes up in practice
A media company stores terabytes of video archives that are accessed once a year for audit purposes. Moving these objects to a cold storage tier (Azure Archive, S3 Glacier, or Google Nearline) costs a fraction of hot storage. Questions like this test whether you understand storage tiers, access frequency tradeoffs, and retrieval latency requirements.
What to study next
Got this wrong? Here's your next step.
Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related DEA-C01 subnetting questions on CIDR, address ranges, and subnet selection.
Data Operations and Support — This question tests Data Operations and Support — CIDR notation defines the prefix length..
What is the correct answer to this question?
The correct answer is: Apply a 'Column masking' transformation to replace values with 'XXX'. — Options A, C, and D are correct. DataBrew provides built-in transformations for masking: 'Column masking' replaces values with a fixed pattern, 'Column hashing' replaces with a hash, and 'Column delete' removes the column. Option B is wrong because 'Column encryption' is not a DataBrew transformation; encryption is typically done at rest or with KMS. Option E is wrong because there is no 'Column tokenization' transformation in DataBrew; tokenization would require a custom recipe step.
What should I do if I get this DEA-C01 question wrong?
Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related DEA-C01 subnetting questions on CIDR, address ranges, and subnet selection.
What is the key concept behind this question?
CIDR notation defines the prefix length.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
This DEA-C01 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the DEA-C01 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.