This DEA-C01 practice question tests your understanding of data store management. 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 uses Amazon Redshift for analytics. The data engineering team wants to improve query performance for frequently used aggregate queries. Which TWO actions would help achieve this?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Use distribution keys to collocate data on the same node slices
Distribution keys determine how data is distributed across node slices in Amazon Redshift. By choosing distribution keys that align with the join and aggregation columns, the database can collocate related data on the same slice, minimizing data movement during query execution. This directly improves performance for aggregate queries by reducing network traffic and enabling local computation.
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 number of WLM query queues
Why it's wrong here
WLM queues manage concurrency, not performance of individual queries.
✓
Use distribution keys to collocate data on the same node slices
Why this is correct
Distribution keys reduce data movement during joins and aggregations.
Related concept
Read the scenario before looking for a memorised answer.
✗
Run the VACUUM command to reclaim space from deleted rows
Why it's wrong here
VACUUM reclaims storage space, not directly improve query performance.
✓
Define appropriate sort keys on the tables
Why this is correct
Sort keys minimize the number of blocks scanned for range-restricted queries.
Related concept
Read the scenario before looking for a memorised answer.
✗
Increase the number of nodes in the cluster
Why it's wrong here
Adding nodes increases cost but may not improve performance if the issue is data distribution.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often confuse VACUUM (which reclaims space) with performance optimization for queries, or assume adding nodes always improves query speed without considering the overhead of data redistribution.
Detailed technical explanation
How to think about this question
In Amazon Redshift, data is distributed across slices using a hash function on the distribution key. For aggregate queries like SUM or COUNT with GROUP BY, if the grouping column matches the distribution key, each slice can compute its partial aggregate locally without reshuffling data. Sort keys further enhance performance by enabling zone maps to skip irrelevant blocks during scans, reducing I/O for range-restricted aggregates. A common real-world scenario is a fact table distributed by a date key, where daily aggregate queries benefit from both collocation and sorted block elimination.
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 healthcare organisation deploys an application with a public-facing web tier and a private database tier. The database subnet has no public IP and only accepts connections from the web tier's security group. Questions like this test whether you can design cloud network isolation using VNets/VPCs, subnets, and security group rules.
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: Use distribution keys to collocate data on the same node slices — Distribution keys determine how data is distributed across node slices in Amazon Redshift. By choosing distribution keys that align with the join and aggregation columns, the database can collocate related data on the same slice, minimizing data movement during query execution. This directly improves performance for aggregate queries by reducing network traffic and enabling local computation.
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.
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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