Quick Answer
The answer is to create read replicas of the RDS instance, as this directly offloads read traffic from the primary database to handle read scaling for high-traffic workloads. By promoting one or more read replicas, the application can route SELECT queries to these copies, reducing the load on the source instance and improving page load times during flash sales without affecting write capacity. On the AWS Certified Database Specialty DBS-C01 exam, this scenario tests your understanding of the fundamental difference between read scaling and high availability—a common trap is confusing Multi-AZ (which only provides failover, not read offloading) with read replicas. Remember that ElastiCache is for caching specific query results, not for scaling general read load, and upgrading the instance is a vertical scaling approach that is less elastic and cost-effective than adding replicas. Memory tip: “Replicas for reads, Multi-AZ for needs”—if the question says “read-heavy” or “read scaling,” always think replicas first.
This DBS-C01 practice question tests your understanding of workload-specific database design. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. 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 has a high-traffic e-commerce application that uses Amazon RDS for MySQL. During flash sales, the database experiences high read load causing slow page loads. The application is read-heavy with occasional writes. Which design change would provide the most immediate performance improvement?
Add an Amazon ElastiCache layer
Why wrong: Caching requires application changes and may miss dynamic data.
Create read replicas of the RDS instance
Read replicas offload read traffic, improving performance.
Enable Multi-AZ deployment
Why wrong: Multi-AZ provides failover, not read scaling.
Upgrade to a larger instance type
Why wrong: Vertical scaling is less elastic and more costly.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
Create read replicas of the RDS instance
Adding read replicas offloads read traffic from the primary instance, improving performance for read-heavy workloads. Option B (Multi-AZ) is wrong because it provides high availability, not read scaling. Option C (ElastiCache) is wrong because it caches only data that is explicitly cached, but read replicas reduce load on the primary. Option D (instance upgrade) is wrong because it can help but is more expensive and less scalable than adding replicas.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
Add an Amazon ElastiCache layer
Why it's wrong here
Caching requires application changes and may miss dynamic data.
Create read replicas of the RDS instance
Why this is correct
Read replicas offload read traffic, improving performance.
Related concept
Read the scenario before looking for a memorised answer.
Enable Multi-AZ deployment
Why it's wrong here
Multi-AZ provides failover, not read scaling.
Upgrade to a larger instance type
Why it's wrong here
Vertical scaling is less elastic and more costly.
Common exam traps
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
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.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
An e-commerce site experiences heavy traffic on Black Friday and near-zero traffic during off-peak weeks. Rather than provisioning permanent large VMs, the team uses auto-scaling groups that add capacity automatically under load and reduce it overnight. Questions like this test whether you understand elasticity, availability zones, and cloud compute scaling patterns.
What to study next
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 — study guide chapter
Learn the concepts, then practise the questions
Workload-Specific Database Design practice questions
Targeted practice on this topic area only
All DBS-C01 questions
1,730 questions across all exam domains
AWS Certified Database Specialty DBS-C01 study guide
Full concept coverage aligned to exam objectives
DBS-C01 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Practise DBS-C01 questions linked to Workload-Specific Database Design.
Practise DBS-C01 questions linked to Deployment and Migration.
Practise DBS-C01 questions linked to Management and Operations.
Practise DBS-C01 questions linked to Monitoring and Troubleshooting.
Practise DBS-C01 questions linked to Database Security.
Practise DBS-C01 questions linked to DBS-C01 fundamentals.
Practise DBS-C01 questions linked to DBS-C01 scenario.
Practise DBS-C01 questions linked to DBS-C01 troubleshooting.
Practice this exam
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Workload-Specific Database Design — This question tests Workload-Specific Database Design — Read the scenario before looking for a memorised answer..
The correct answer is: Create read replicas of the RDS instance — Adding read replicas offloads read traffic from the primary instance, improving performance for read-heavy workloads. Option B (Multi-AZ) is wrong because it provides high availability, not read scaling. Option C (ElastiCache) is wrong because it caches only data that is explicitly cached, but read replicas reduce load on the primary. Option D (instance upgrade) is wrong because it can help but is more expensive and less scalable than adding replicas.
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.
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 →
Same concept, more angles
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 e-commerce platform. The application team reports increasing read latency on the primary instance during sales events. Which action should be taken to reduce read load on the primary?
mediumWhy C: Creating one or more read replicas offloads read traffic from the primary RDS for PostgreSQL instance, directly addressing the increased read latency during sales events. Read replicas are asynchronous replicas that can serve SELECT queries, reducing the load on the primary without requiring application changes to the write path. This is the standard AWS solution for scaling read-heavy workloads in RDS.
Last reviewed: Jun 20, 2026
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.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.