Question 210 of 1,750
Monitoring and LogginghardMultiple ChoiceObjective-mapped

How to Cost-Effectively Monitor RDS PostgreSQL Active Connections and Query Execution Time

This DOP-C02 practice question tests your understanding of monitoring and logging. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. A key principle to apply: amazon RDS Performance Insights. 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 critical application on Amazon RDS for PostgreSQL. The database experiences periodic slowdowns. The team wants to monitor the number of active connections and the query execution time. Which approach is most cost-effective?

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 Performance Insights and set up CloudWatch alarms on the 'DBLoad' metric.

Option C is correct because Performance Insights provides detailed query execution time metrics, enabling monitoring of query performance. It also includes the 'DBLoad' metric which reflects database load from active connections and queries. Combined with CloudWatch alarms, this approach is cost-effective as Performance Insights is included with RDS at no additional cost for up to 7 days of retention (longer retention has a fee). Options A and B are invalid because the CloudWatch agent cannot be installed on RDS instances, and 'QueryExecutionTime' is not a standard CloudWatch metric for RDS. Option D is less suitable for the specific requirement of query execution time; Enhanced Monitoring provides OS-level metrics like processes and memory but does not track query-level execution time.

Key principle: Amazon RDS Performance Insights

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

  • Install the CloudWatch agent on the RDS instance to collect custom metrics.

    Why it's wrong here

    Incorrect. The CloudWatch agent cannot be installed on RDS instances; RDS is a managed service and does not allow installation of the CloudWatch agent.

  • Use the RDS console to view the 'DatabaseConnections' and 'QueryExecutionTime' metrics.

    Why it's wrong here

    Incorrect. The RDS console does not expose a 'QueryExecutionTime' metric. 'DatabaseConnections' is available, but the requirement includes query execution time, which is not provided by this approach.

  • Enable Performance Insights and set up CloudWatch alarms on the 'DBLoad' metric.

    Why this is correct

    Correct. Performance Insights provides per-query execution time and the 'DBLoad' metric, which can be monitored via CloudWatch alarms. It is included with RDS at no additional cost for basic retention, making it cost-effective.

    Related concept

    Amazon RDS Performance Insights

  • Enable Enhanced Monitoring and publish metrics to CloudWatch, then create alarms on relevant metrics.

    Why it's wrong here

    Incorrect. Enhanced Monitoring provides OS-level metrics (e.g., CPU, memory, disk I/O) but does not include query execution time. It cannot fulfill the requirement to monitor query execution time.

Common exam traps

Common exam trap: answer the scenario, not the keyword

Candidates often assume Enhanced Monitoring is the most cost-effective because it is free, but it lacks query-level performance data. The key is that Performance Insights tracks execution time natively and is included at no extra cost for the first 7 days, making it the correct choice for this requirement.

Detailed technical explanation

How to think about this question

Enhanced Monitoring collects metrics from the RDS host's operating system using a lightweight agent that runs in a separate, isolated process. It publishes metrics such as 'ActiveConnections' (derived from the number of established TCP connections to the database) and 'DiskQueueDepth' to CloudWatch at configurable intervals (1, 5, 10, 15, 30, or 60 seconds). For query execution time, you would typically enable Performance Insights or use RDS's built-in pg_stat_statements extension to capture query-level metrics, then publish those to CloudWatch via a custom script or Lambda function. In a real-world scenario, a team might combine Enhanced Monitoring for connection counts with Performance Insights for query latency, but the question asks for the most cost-effective single approach; Enhanced Monitoring alone provides the connection count and can be paired with basic RDS logging to infer execution time trends without additional costs.

KKey Concepts to Remember

  • Amazon RDS Performance Insights
  • Enhanced Monitoring
  • DBLoad

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

Amazon RDS Performance Insights

Real-world example

How this comes up in practice

A startup's cloud architect reviews their monthly bill and notices costs are higher than expected for a long-running batch job. Switching from on-demand instances to Reserved Instances — or using Spot/Preemptible VMs — can reduce compute costs by up to 72 %. Questions like this test whether you understand the tradeoffs between commitment, flexibility, and cost across cloud pricing models.

What to study next

Got this wrong? Here's your next step.

Review amazon RDS Performance Insights, then practise related DOP-C02 questions on the same topic to reinforce the concept.

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FAQ

Questions learners often ask

What does this DOP-C02 question test?

Monitoring and Logging — This question tests Monitoring and Logging — Amazon RDS Performance Insights.

What is the correct answer to this question?

The correct answer is: Enable Performance Insights and set up CloudWatch alarms on the 'DBLoad' metric. — Option C is correct because Performance Insights provides detailed query execution time metrics, enabling monitoring of query performance. It also includes the 'DBLoad' metric which reflects database load from active connections and queries. Combined with CloudWatch alarms, this approach is cost-effective as Performance Insights is included with RDS at no additional cost for up to 7 days of retention (longer retention has a fee). Options A and B are invalid because the CloudWatch agent cannot be installed on RDS instances, and 'QueryExecutionTime' is not a standard CloudWatch metric for RDS. Option D is less suitable for the specific requirement of query execution time; Enhanced Monitoring provides OS-level metrics like processes and memory but does not track query-level execution time.

What should I do if I get this DOP-C02 question wrong?

Review amazon RDS Performance Insights, then practise related DOP-C02 questions on the same topic to reinforce the concept.

What is the key concept behind this question?

Amazon RDS Performance Insights

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Last reviewed: Jul 4, 2026

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This DOP-C02 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 DOP-C02 exam.