The answer is Amazon DynamoDB with a global secondary index on score. This design is correct because a DynamoDB GSI allows you to query items by an alternate key—here, the score attribute—enabling efficient retrieval of top players via a sorted query on the index, while a separate query on the base table can fetch an individual player’s rank by their unique identifier. On the AWS Certified Database Specialty DBS-C01 exam, this scenario tests your understanding of when to use DynamoDB’s flexible indexing over relational databases or caching layers; a common trap is choosing ElastiCache sorted sets for their speed, but the exam emphasizes durability and persistence for a leaderboard that must survive restarts. Remember the memory tip: “GSI sorts scores, base table stores stories”—the index handles the ranking order, while the main table holds the full player data for rank lookups.
DBS-C01 Workload-Specific Database Design Practice Question
This DBS-C01 practice question tests your understanding of workload-specific database design. Compare every option against the stated constraints before choosing — the best answer satisfies all requirements, not just the most obvious one. 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 building a real-time leaderboard for a gaming application. The leaderboard must update scores within seconds and support queries for top players and individual ranks. Which database design is most appropriate?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Amazon DynamoDB with a global secondary index on score
Amazon DynamoDB with a global secondary index (GSI) on score can efficiently query top players and individual ranks. Option A (Amazon RDS with ORDER BY) becomes slow at scale. Option C (Amazon ElastiCache sorted sets) is good for leaderboards but not durable. Option D (Amazon S3) is not suitable for real-time updates.
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.
✗
Amazon S3 with Range GET requests
Why it's wrong here
S3 is not meant for real-time transactional updates.
✗
Amazon ElastiCache for Redis with sorted sets
Why it's wrong here
Redis is in-memory and not designed for durable persistence as a primary database.
✓
Amazon DynamoDB with a global secondary index on score
Why this is correct
DynamoDB GSI enables efficient querying of top scores and rank lookups.
Related concept
Read the scenario before looking for a memorised answer.
✗
Amazon RDS for PostgreSQL with ORDER BY and LIMIT
Why it's wrong here
Relational databases struggle with high write throughput and large leaderboard queries.
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 DBS-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.
Workload-Specific Database Design — This question tests Workload-Specific Database Design — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Amazon DynamoDB with a global secondary index on score — Amazon DynamoDB with a global secondary index (GSI) on score can efficiently query top players and individual ranks. Option A (Amazon RDS with ORDER BY) becomes slow at scale. Option C (Amazon ElastiCache sorted sets) is good for leaderboards but not durable. Option D (Amazon S3) is not suitable for real-time updates.
What should I do if I get this DBS-C01 question wrong?
Identify which DBS-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.
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 →
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A startup is building a real-time leaderboard for a gaming application. The data is highly dynamic with frequent updates and requires single-digit millisecond latency. Which database is most suitable?
easy
A.Amazon Neptune
B.Amazon Redshift
✓ C.Amazon DynamoDB
D.Amazon RDS for PostgreSQL
Why C: Amazon DynamoDB is the most suitable choice because it is a fully managed NoSQL key-value and document database that delivers single-digit millisecond latency at any scale, making it ideal for real-time leaderboards with high-frequency updates. Its DAX (DynamoDB Accelerator) caching layer can further reduce read latency to microseconds, while its auto-scaling and on-demand capacity modes handle the highly dynamic workload without downtime.
Last reviewed: Jun 20, 2026
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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.
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