DBS-C01 Workload-Specific Database Design Practice Question
A company is designing a database for a real-time leaderboard in a mobile game. The leaderboard updates thousands of times per second and must return the top 100 scores with minimal latency. Which AWS database service is most suitable for this workload?
⚠ Common exam trap
It's easy for candidates to choose DynamoDB because of its fast key-value lookups, overlooking that leaderboard ranking requires sorted range queries across all items, which DynamoDB cannot perform efficiently without expensive full table scans or custom sharding logic.
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
✓
Amazon ElastiCache for Redis
Amazon ElastiCache for Redis is the most suitable choice because Redis provides an in-memory data structure server with a Sorted Set data type (ZADD and ZRANGE commands) that natively supports real-time leaderboard operations. It can handle thousands of writes per second with sub-millisecond latency and efficiently retrieve the top 100 scores using ZREVRANGE with a time complexity of O(log(N)+M), where M is the number of returned elements.
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 Neptune
Why it's wrong here
Neptune is a graph database not designed for leaderboards.
- ✓
Amazon ElastiCache for Redis
Why this is correct
Redis sorted sets provide efficient leaderboard operations.
- ✗
Amazon DynamoDB
Why it's wrong here
DynamoDB is not optimized for real-time sorted queries with frequent updates.
- ✗
Amazon Aurora
Why it's wrong here
Aurora is a relational database with higher latency for this use case.
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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.