DBS-C01 Workload-Specific Database Design Practice Question
A company is designing a database for a global e-commerce application that requires low-latency reads and writes with strong consistency. The application is expected to handle millions of requests per second and requires high availability. Which AWS database service is most suitable for this workload?
⚠ Common exam trap
Test-takers frequently confuse Amazon ElastiCache as a primary database solution for low-latency workloads, overlooking that it lacks durability and strong consistency, and instead choose it over DynamoDB with DAX which is purpose-built for such requirements.
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 DynamoDB with DynamoDB Accelerator (DAX)
Amazon DynamoDB with DAX is the most suitable choice because DynamoDB itself provides single-digit millisecond latency at any scale, supports strong consistency for both reads and writes (via ConsistentRead=true for reads), and is designed for high availability and millions of requests per second. DAX is an in-memory cache that accelerates reads, but it only supports eventual consistency; however, reads requiring strong consistency can be served directly from DynamoDB while DAX handles the majority of eventually consistent reads, thereby meeting the low-latency and strong consistency requirements of the application.
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 ElastiCache for Memcached
Why it's wrong here
ElastiCache is a caching layer, not a primary database, and lacks persistence and strong consistency guarantees.
- ✗
Amazon S3 with S3 Select
Why it's wrong here
S3 is object storage not designed for low-latency transactional workloads.
- ✗
Amazon RDS for MySQL with Multi-AZ deployment
Why it's wrong here
RDS MySQL does not scale horizontally to millions of requests per second in the same way as DynamoDB.
- ✓
Amazon DynamoDB with DynamoDB Accelerator (DAX)
Why this is correct
DynamoDB provides scalable, low-latency, strongly consistent performance suitable for high-request-rate applications.
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Written by Johnson Ajibi, MSc IT Security
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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.