- A
Enable the slow query log in RDS and review the logs.
Slow query log records queries that take a long time to execute.
- B
Increase the DB instance size to improve performance.
Why wrong: Scaling up is not a diagnostic action; it may mask the problem.
- C
Enable Performance Insights to analyze database performance.
Performance Insights identifies top SQL and wait events.
- D
Use the RDS console to review metrics for high CPU or IOPS usage.
High CPU/IOPS can indicate problematic queries.
- E
Create a read replica to offload read traffic.
Why wrong: Read replicas help with read scaling, not diagnosing slow queries.
Question 1,237 of 1,616
How to Diagnose Slow Queries in Amazon RDS MySQL
This DVA-C02 practice question tests your understanding of troubleshooting and optimization. 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 developer is using Amazon RDS for MySQL and notices that the database performance has degraded. The developer suspects that slow queries are the cause. Which THREE actions should the developer take to identify and address the slow queries?
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
✓
Enable the slow query log in RDS and review the logs.
Options A, C, and D are correct actions to identify and address slow queries in Amazon RDS for MySQL. Option A: Enabling the slow query log captures queries that exceed a specified execution time, allowing the developer to review and optimize them. Option C: Performance Insights provides a dashboard that visualizes database load, wait events, and top SQL queries, helping to pinpoint bottlenecks. Option D: Reviewing metrics for high CPU or IOPS usage can indicate whether hardware resources are exhausted due to inefficient queries, guiding further investigation. Option B is incorrect because increasing the DB instance size is a reactive scaling measure that may temporarily alleviate performance issues but does not help identify the root cause of slow queries. Option E is incorrect because creating a read replica offloads read traffic and improves read scalability, but it does not directly assist in diagnosing or addressing slow query performance on the primary instance.
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.
- ✓
Enable the slow query log in RDS and review the logs.
Why this is correct
Slow query log records queries that take a long time to execute.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Increase the DB instance size to improve performance.
Why it's wrong here
Scaling up is not a diagnostic action; it may mask the problem.
- ✓
Enable Performance Insights to analyze database performance.
Why this is correct
Performance Insights identifies top SQL and wait events.
Related concept
Read the scenario before looking for a memorised answer.
- ✓
Use the RDS console to review metrics for high CPU or IOPS usage.
Why this is correct
High CPU/IOPS can indicate problematic queries.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Create a read replica to offload read traffic.
Why it's wrong here
Read replicas help with read scaling, not diagnosing slow queries.
Common exam traps
Common exam trap: answer the scenario, not the keyword
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
How to think about this question
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.
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.
- Use explanations to understand the rule behind the answer.
TExam Day Tips
- Underline the problem statement mentally.
- 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 DVA-C02 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.
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Troubleshooting and Optimization — study guide chapter
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FAQ
Questions learners often ask
What does this DVA-C02 question test?
Troubleshooting and Optimization — This question tests Troubleshooting and Optimization — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Enable the slow query log in RDS and review the logs. — Options A, C, and D are correct actions to identify and address slow queries in Amazon RDS for MySQL. Option A: Enabling the slow query log captures queries that exceed a specified execution time, allowing the developer to review and optimize them. Option C: Performance Insights provides a dashboard that visualizes database load, wait events, and top SQL queries, helping to pinpoint bottlenecks. Option D: Reviewing metrics for high CPU or IOPS usage can indicate whether hardware resources are exhausted due to inefficient queries, guiding further investigation. Option B is incorrect because increasing the DB instance size is a reactive scaling measure that may temporarily alleviate performance issues but does not help identify the root cause of slow queries. Option E is incorrect because creating a read replica offloads read traffic and improves read scalability, but it does not directly assist in diagnosing or addressing slow query performance on the primary instance.
What should I do if I get this DVA-C02 question wrong?
Identify which DVA-C02 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.
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 →
Same concept, more angles
3 more ways this is tested on DVA-C02
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 developer is troubleshooting a slow-performing Amazon RDS for MySQL database. Which TWO actions should the developer take to improve query performance?
medium- A.Delete unused indexes to reduce write overhead.
- B.Enable Multi-AZ deployment for better read performance.
- ✓ C.Increase the instance size to provide more CPU and memory.
- ✓ D.Enable the slow query log to identify poorly performing queries.
- E.Delete the binary log files to free up storage.
Why C: Option C is correct because increasing the instance size provides more CPU and memory, which can improve query processing speed. Option D is correct because enabling the slow query log allows you to identify and analyze poorly performing queries so you can optimize them. Option A is incorrect: while deleting unused indexes reduces write overhead, indexes typically improve read performance, so removing them would not help with slow queries. Option B is incorrect: Multi-AZ deployment is for high availability and failover, not for improving read performance; read replicas would be more appropriate. Option E is incorrect: deleting binary log files frees storage but does not directly improve query performance.
Variation 2. A developer is troubleshooting a slow Amazon RDS MySQL database query. The query is frequently executed and takes 5 seconds to complete. Which AWS service should the developer use to analyze the query performance?
easy- A.AWS CloudTrail
- ✓ B.Amazon RDS Performance Insights
- C.Amazon CloudWatch Logs
- D.AWS X-Ray
Why B: Amazon RDS Performance Insights is the correct service for analyzing Amazon RDS database query performance. It provides a visual dashboard to analyze database load, identify top queries by various metrics like latency, and pinpoint performance bottlenecks. AWS CloudTrail (Option A) records API activity, not database query details. Amazon CloudWatch Logs (Option C) collects log data but does not offer query-level performance analysis. AWS X-Ray (Option D) is used for tracing requests in distributed applications, not for database query analysis.
Variation 3. A developer is troubleshooting a slow-running query on an Amazon RDS for MySQL database. The query is used by a reporting application and takes over 30 seconds to complete. The database is a db.r5.large instance with 200 GB of gp2 storage. Which TWO actions should the developer take to improve query performance?
medium- A.Terminate idle connections to free up resources.
- ✓ B.Review the slow query log to identify the query and its execution plan.
- C.Increase the allocated storage to 500 GB to improve I/O performance.
- ✓ D.Add appropriate indexes to the tables involved in the query.
- E.Enable Multi-AZ deployment for better read performance.
Why B: Option B is correct: reviewing the slow query log helps identify the query and its execution plan, which is essential for diagnosing performance issues. Option D is correct: adding appropriate indexes can speed up query execution by reducing the number of rows scanned. Option A is incorrect: terminating idle connections frees up resources but does not directly improve query performance for a slow-running query. Option C is incorrect: increasing storage to gp2 does not improve I/O performance; gp2 performance scales with size only up to a point, but the primary bottleneck is likely query optimization, not storage. Option E is incorrect: Multi-AZ is for high availability and failover, not for enhancing read performance.
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Last reviewed: Jun 20, 2026
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