← DEA-C01·Amazon Web Services

Question 666 of 1,786

Data Store Management →mediumMultiple ChoiceObjective-mapped

RDS Read Replicas: Improving Read Performance

This DEA-C01 practice question tests your understanding of data store management. 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 runs a production Amazon RDS for MySQL database with Multi-AZ deployment. The database experiences high read latency during peak hours. The company wants to improve read performance with minimal application changes. Which solution should a data engineer recommend?

A
Create one or more read replicas in a different Availability Zone.
Read replicas offload read traffic from the primary instance.
B
Use Amazon DynamoDB Accelerator (DAX) as a caching layer.
Why wrong: DAX is for DynamoDB, not RDS MySQL.
C
Increase the DB instance size to a larger instance class.
Why wrong: Scaling up may help but is more costly and doesn't offload reads as efficiently.
D
Enable Multi-AZ on the existing instance.
Why wrong: Multi-AZ improves availability, not read performance.

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 in a different Availability Zone.

Creating read replicas in a different Availability Zone offloads read traffic from the primary DB instance, reducing read latency during peak hours. Read replicas in Amazon RDS for MySQL are asynchronous replicas that can serve SELECT queries, requiring minimal application changes (only a new connection endpoint). This directly addresses high read latency without altering the existing Multi-AZ setup.

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.

✓
Create one or more read replicas in a different Availability Zone.
Why this is correct
Read replicas offload read traffic from the primary instance.
Related concept
Read the scenario before looking for a memorised answer.
✗
Use Amazon DynamoDB Accelerator (DAX) as a caching layer.
Why it's wrong here
DAX is for DynamoDB, not RDS MySQL.
✗
Increase the DB instance size to a larger instance class.
Why it's wrong here
Scaling up may help but is more costly and doesn't offload reads as efficiently.
✗
Enable Multi-AZ on the existing instance.
Why it's wrong here
Multi-AZ improves availability, not read performance.

Common exam traps

Common exam trap: answer the scenario, not the keyword

The trap here is that candidates confuse Multi-AZ with read scaling, assuming the standby instance can serve reads, but in Amazon RDS for MySQL, the Multi-AZ standby is passive and cannot accept connections until failover occurs.

Detailed technical explanation

How to think about this question

Amazon RDS for MySQL read replicas use MySQL's native asynchronous replication, where the primary writes binary log events and replicas apply them. Under the hood, read replicas can be promoted to standalone instances and support lag monitoring via the `ReplicaLag` metric. In a real-world scenario, if the application's read workload is bursty (e.g., reporting queries), read replicas can absorb the load while the primary handles writes, with typical replication lag under 100 ms in the same region.

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

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

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 DEA-C01 practice-question pages

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

Data Ingestion and Transformation practice questions

Practise DEA-C01 questions linked to Data Ingestion and Transformation.

Data Operations and Support practice questions

Practise DEA-C01 questions linked to Data Operations and Support.

Data Security and Governance practice questions

Practise DEA-C01 questions linked to Data Security and Governance.

Data Store Management practice questions

Practise DEA-C01 questions linked to Data Store Management.

DEA-C01 fundamentals practice questions

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

DEA-C01 scenario practice questions

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

DEA-C01 troubleshooting practice questions

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

Practice this exam

Start a free DEA-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

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

FAQ

Questions learners often ask

What does this DEA-C01 question test?

Data Store Management — This question tests Data Store Management — 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 in a different Availability Zone. — Creating read replicas in a different Availability Zone offloads read traffic from the primary DB instance, reducing read latency during peak hours. Read replicas in Amazon RDS for MySQL are asynchronous replicas that can serve SELECT queries, requiring minimal application changes (only a new connection endpoint). This directly addresses high read latency without altering the existing Multi-AZ setup.

What should I do if I get this DEA-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

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 DEA-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 DEA-C01 exam.