← DBS-C01·Amazon Web Services

Question 1,271 of 1,730

Workload-Specific Database Design →easyMultiple ChoiceObjective-mapped

Read Replicas for RDS MySQL

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 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?

A
Implement an Amazon ElastiCache Redis cluster in front of the database.
Why wrong: ElastiCache requires application code changes to cache query results.
B
Create one or more read replicas of the RDS DB instance.
Read replicas offload read traffic from the primary instance, improving read performance without application changes.
C
Increase the instance size of the RDS DB instance.
Why wrong: Vertical scaling may improve performance but is not the most cost-effective or targeted solution for read-heavy workloads.
D
Enable DynamoDB Accelerator (DAX) for the RDS instance.
Why wrong: DAX is a caching service for DynamoDB, not for RDS MySQL.

Full breakdown with real-world context →

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.

Option B is correct because 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.

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.

✗
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.
Related concept
Read the scenario before looking for a memorised answer.
✗
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.

Common exam traps

Common exam trap: answer the scenario, not the keyword

The trap here is that candidates may 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.

Detailed technical explanation

How to think about this question

Amazon RDS read replicas use MySQL's native asynchronous replication to maintain a consistent copy of the database. The replica can be promoted to a standalone instance in case of primary failure, but during normal operation it serves read traffic with minimal replication lag (typically sub-second). In a real-world scenario, you can create multiple read replicas and use a Route 53 weighted record set or a connection pool like ProxySQL to distribute reads, achieving linear read scaling without application changes.

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.

TExam Day Tips

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 cloud solutions architect for a retail company is evaluating services for a new workload. The correct answer here reflects best practice for the specific scenario described — not a general cloud recommendation. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Cloud exam questions reward reading the constraint carefully: the same technology can be right or wrong depending on the use case.

What to study next

Got this wrong? Here's your next step.

Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.

Related DBS-C01 practice-question pages

Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.

Workload-Specific Database Design practice questions

Practise DBS-C01 questions linked to Workload-Specific Database Design.

Deployment and Migration practice questions

Practise DBS-C01 questions linked to Deployment and Migration.

Management and Operations practice questions

Practise DBS-C01 questions linked to Management and Operations.

Monitoring and Troubleshooting practice questions

Practise DBS-C01 questions linked to Monitoring and Troubleshooting.

Database Security practice questions

Practise DBS-C01 questions linked to Database Security.

DBS-C01 fundamentals practice questions

Practise DBS-C01 questions linked to DBS-C01 fundamentals.

DBS-C01 scenario practice questions

Practise DBS-C01 questions linked to DBS-C01 scenario.

DBS-C01 troubleshooting practice questions

Practise DBS-C01 questions linked to DBS-C01 troubleshooting.

Practice this exam

Start a free DBS-C01 practice session

Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.

10 questions 20 questions 30 questions 50 questions Timed 30

DBS-C01 practice-test guide →Study guide →Browse all practice tests

FAQ

Questions learners often ask

What does this DBS-C01 question test?

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: Create one or more read replicas of the RDS DB instance. — Option B is correct because 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.

What should I do if I get this DBS-C01 question wrong?

Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.

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 →

How Courseiva writes practice questions · Editorial policy

Same concept, more angles

1 more ways 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: Option C is correct because 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.

Keep practising

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.

Loading comments…

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.