The answer is to perform a DEEP COPY on the largest tables. This is correct because a DEEP COPY physically rewrites the table with a fresh, optimally sorted and compressed storage layout, reclaiming space that VACUUM alone cannot recover. While VACUUM reorganizes and reclaims space from deleted rows, it does not re-apply compression or rebuild the underlying storage blocks, leaving suboptimal encodings and fragmentation intact. On the AWS Certified Data Engineer Associate DEA-C01 exam, this question tests your understanding of Redshift’s storage mechanics and the distinction between VACUUM and DEEP COPY for reclaiming storage. A common trap is assuming VACUUM always reduces storage, but it only marks space as reusable, not physically freed. Remember the mnemonic: VACUUM vacuums the floor, DEEP COPY digs up and replaces the tiles.
DEA-C01 Data Store Management Practice Question
This DEA-C01 practice question tests your understanding of data store management. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. 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 data engineer notices that an Amazon Redshift cluster's storage utilization has grown unexpectedly. The cluster uses automatic compression and has a mix of fact and dimension tables. The engineer runs VACUUM and ANALYZE, but storage does not decrease. Which action is most likely to reduce storage consumption?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Perform a DEEP COPY on the largest tables.
Option A is correct because DEEP COPY recreates the table with a fresh, optimally sorted and compressed storage layout, reclaiming space that VACUUM alone cannot recover. In Redshift, VACUUM reorganizes and reclaims space from deleted rows but does not re-apply compression or rebuild the underlying storage blocks; DEEP COPY (e.g., using CREATE TABLE AS or the DEEP COPY command) physically rewrites the data, eliminating fragmentation and applying the current compression encoding, which can significantly reduce storage consumption when automatic compression has left suboptimal encodings or when historical updates have bloated the table.
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.
✓
Perform a DEEP COPY on the largest tables.
Why this is correct
DEEP COPY recreates the table with optimal compression, reclaiming storage from deleted rows and reorganizing data.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
Run VACUUM with the BOOST option.
Why it's wrong here
VACUUM reclaims space from deleted rows, but if no significant deletes occurred, it won't reduce storage; DEEP COPY is more effective.
✗
Run ANALYZE with the FULL keyword on all tables.
Why it's wrong here
ANALYZE updates query statistics but does not physically delete data or reclaim storage.
✗
Modify the sort key on the largest tables to a more selective column.
Why it's wrong here
Changing sort keys does not free up storage; it only reorders data.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates confuse VACUUM's space reclamation (which only removes deleted rows) with the need to physically rebuild the table to reapply compression, assuming VACUUM or ANALYZE can fix storage bloat caused by suboptimal encodings.
Detailed technical explanation
How to think about this question
Under the hood, Redshift stores data in 1 MB blocks per column, and automatic compression assigns encoding based on a sample of rows during initial load; subsequent inserts or updates can lead to suboptimal encodings that VACUUM does not re-evaluate. DEEP COPY forces a full table rebuild, allowing Redshift to re-sample the entire dataset and apply the best compression encoding for each column, often achieving 20-50% storage savings in practice. A real-world scenario is a fact table that has grown through many incremental loads with varying data distributions, where automatic compression encodings chosen early become inefficient as data skew changes.
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.
TExam Day Tips
→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 exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Data Store Management — This question tests Data Store Management — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Perform a DEEP COPY on the largest tables. — Option A is correct because DEEP COPY recreates the table with a fresh, optimally sorted and compressed storage layout, reclaiming space that VACUUM alone cannot recover. In Redshift, VACUUM reorganizes and reclaims space from deleted rows but does not re-apply compression or rebuild the underlying storage blocks; DEEP COPY (e.g., using CREATE TABLE AS or the DEEP COPY command) physically rewrites the data, eliminating fragmentation and applying the current compression encoding, which can significantly reduce storage consumption when automatic compression has left suboptimal encodings or when historical updates have bloated the table.
What should I do if I get this DEA-C01 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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.