The correct answer is to resize the cluster to include additional nodes, as this directly addresses the root cause of Redshift cluster performance degradation caused by high disk space usage. When disk utilization exceeds 80% on many nodes, the cluster experiences increased I/O contention and reduced query throughput because the database engine struggles to allocate temporary storage for large joins and aggregations. Resizing adds both compute capacity and physical storage, relieving disk pressure and restoring performance. On the AWS Certified Data Engineer Associate DEA-C01 exam, this scenario tests your understanding that while vacuuming or compression can reclaim space, they do not add hardware capacity—a common trap where candidates confuse maintenance with scaling. Remember the memory tip: “Disk above 80? Add a node, don’t just clean.” This distinguishes between temporary fixes and the long-term solution required for sustained performance.
DEA-C01 Data Operations and Support Practice Question
This DEA-C01 practice question tests your understanding of data operations and support. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. 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 runs an Amazon Redshift cluster for analytics. During peak hours, query performance degrades significantly. The data engineer notices that disk space usage is above 80% on many nodes. Which of the following is the MOST effective long-term solution to improve query performance?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Resize the cluster to include additional nodes.
Resizing the cluster to add more nodes increases total storage and compute capacity, reducing disk pressure and improving performance. Option A is wrong because vacuuming reclaims space but does not add capacity. Option B is wrong because compression helps but may not be sufficient. Option D is wrong because it only addresses queries waiting for resources.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
Increase the workload management (WLM) queue slots.
Why it's wrong here
WLM changes affect concurrency but not disk space.
✓
Resize the cluster to include additional nodes.
Why this is correct
Adding nodes increases both storage and compute resources, directly addressing disk usage and performance.
Related concept
Read the scenario before looking for a memorised answer.
✗
Apply compression encoding to all columns.
Why it's wrong here
Compression reduces storage per row but may not be enough to bring usage below 80%.
✗
Run the VACUUM command to reclaim space.
Why it's wrong here
VACUUM reclaims space from deleted rows but does not increase total capacity.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.
Detailed technical explanation
How to think about this question
This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
Use explanations to understand the rule behind the answer.
TExam Day Tips
→Underline the problem statement mentally.
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
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.
Identify which DEA-C01 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
Data Operations and Support — This question tests Data Operations and Support — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Resize the cluster to include additional nodes. — Resizing the cluster to add more nodes increases total storage and compute capacity, reducing disk pressure and improving performance. Option A is wrong because vacuuming reclaims space but does not add capacity. Option B is wrong because compression helps but may not be sufficient. Option D is wrong because it only addresses queries waiting for resources.
What should I do if I get this DEA-C01 question wrong?
Identify which DEA-C01 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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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
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