DBS-C01 Management and Operations Practice Question
A company is using Amazon Redshift for data warehousing. They notice that query performance has degraded over time. The database administrator checks the system tables and finds that there is significant skew in data distribution across slices. What action should be taken to improve query performance?
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Recreate the table with a different distribution style, such as KEY distribution on a column with high cardinality.
Data skew causes some slices to have more data, leading to slower queries. Recreating the table with a different distribution style, such as KEY distribution on a column with high cardinality, can distribute data more evenly across slices. Option B is incorrect because adding more nodes does not automatically redistribute existing data; the skewed distribution persists. Option C is incorrect because running VACUUM reclaims space and updates statistics but does not address data skew. Option D is incorrect because modifying sort keys improves query performance by optimizing data ordering but does not fix uneven data distribution across slices.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Recreate the table with a different distribution style, such as KEY distribution on a column with high cardinality.
Why this is correct
Changing distribution style can redistribute data evenly across slices, reducing skew.
- ✗
Increase the number of nodes in the cluster.
Why it's wrong here
Adding nodes may help with performance but does not fix existing data skew.
- ✗
Run the VACUUM command to reclaim space and update statistics.
Why it's wrong here
VACUUM reclaims space and updates statistics but does not redistribute data.
- ✗
Modify the sort keys to better match the query patterns.
Why it's wrong here
Sort keys improve query performance but do not address data skew.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This DBS-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 DBS-C01 exam.