DBS-C01 Workload-Specific Database Design Practice Question
A company is running a MySQL database on Amazon RDS for a web application. The application experiences read-heavy traffic, and the company wants to improve read performance without changing the application code. Which design should the database specialist recommend?
⚠ Common exam trap
Many exam-takers confuse read replicas with caching solutions like ElastiCache, but the key constraint is 'without changing the application code' — read replicas require only a connection string change, whereas caching requires code modifications to implement cache 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
✓
Create one or more read replicas of the RDS DB instance.
Amazon RDS read replicas allow you to offload read traffic from the primary DB instance without any application code changes. The application simply connects to the read replica endpoint(s) for SELECT queries, while writes continue to the primary instance. This directly addresses the read-heavy workload by distributing read requests across multiple copies of the database.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Implement an Amazon ElastiCache Redis cluster in front of the database.
Why it's wrong here
ElastiCache requires application code changes to cache query results.
- ✓
Create one or more read replicas of the RDS DB instance.
Why this is correct
Read replicas offload read traffic from the primary instance, improving read performance without application changes.
- ✗
Increase the instance size of the RDS DB instance.
Why it's wrong here
Vertical scaling may improve performance but is not the most cost-effective or targeted solution for read-heavy workloads.
- ✗
Enable DynamoDB Accelerator (DAX) for the RDS instance.
Why it's wrong here
DAX is a caching service for DynamoDB, not for RDS MySQL.
Go deeper
Related to this question
About these practice questions
This DBS-C01 question is part of Courseiva's 1,663-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
Same concept, more angles
1 more way this is tested on DBS-C01
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 company uses Amazon RDS for PostgreSQL for its CRM application. The application experiences intermittent spikes in read traffic. Which TWO actions can the company take to improve read scalability with minimal application changes?
easy- A.Enable Multi-AZ deployment for automatic failover.
- B.Migrate to Amazon Aurora and enable Auto Scaling.
- ✓ C.Create one or more read replicas in the same region.
- D.Upgrade to a larger DB instance class.
- ✓ E.Enable Amazon RDS Proxy to manage database connections.
Why C: Creating read replicas in Amazon RDS for PostgreSQL offloads read traffic from the primary DB instance, directly addressing intermittent read spikes with minimal application changes. Read replicas are asynchronous replicas that can serve read queries, and the application only needs to update its connection string to point to the replica endpoint for read operations.
JA
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.