Question 1,421 of 1,730
Monitoring and TroubleshootinghardMultiple SelectObjective-mapped

Quick Answer

The answer is to create a read replica and switch from General Purpose SSD (gp2) to Provisioned IOPS SSD (io1) with a higher IOPS rate. This is correct because high read latency on RDS PostgreSQL is often an I/O bottleneck, not a compute one—low CPU utilization confirms the instance isn’t starved for processing power. A read replica offloads read-heavy workloads from the primary, directly reducing read IOPS and latency, while io1 provides consistent, higher IOPS performance for the remaining write operations. On the AWS Certified Database Specialty DBS-C01 exam, this scenario tests your ability to distinguish between scaling compute (larger instance) and scaling I/O (storage type or replicas); a common trap is choosing a larger instance when CPU is low. Remember: low CPU + high read latency = I/O problem, so think “replica for reads, io1 for speed.”

DBS-C01 Monitoring and Troubleshooting Practice Question

This DBS-C01 practice question tests your understanding of monitoring and troubleshooting. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. 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 database engineer is troubleshooting slow query performance on an Amazon RDS for PostgreSQL instance. The instance is db.r5.large with 500 GB of General Purpose SSD (gp2) storage. CloudWatch metrics show high Read Latency and high Read IOPS, but low CPU utilization. Which TWO actions should the engineer take to improve performance?

Question 1hardmulti select
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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 a read replica and offload read queries to it.

A is correct because creating a read replica offloads read queries from the primary instance, reducing the read IOPS and read latency on the primary. This directly addresses the high Read Latency and high Read IOPS metrics without requiring a larger instance class or storage change, especially since CPU utilization is low, indicating the bottleneck is I/O, not compute.

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 a read replica and offload read queries to it.

    Why this is correct

    Read replicas reduce the read IOPS on the primary, which can lower latency on the primary.

    Related concept

    Read the scenario before looking for a memorised answer.

  • Increase the DB instance class to a larger size, such as db.r5.2xlarge.

    Why it's wrong here

    Larger instance provides more CPU and memory but does not directly improve storage latency.

  • Enable Multi-AZ to use the standby for read traffic.

    Why it's wrong here

    Standby instances in Multi-AZ are not used for reads.

  • Optimize queries by adding appropriate indexes.

    Why it's wrong here

    While indexing can reduce IOPS, the metrics suggest a storage bottleneck; indexing is application-specific and not directly indicated.

  • Switch from General Purpose SSD (gp2) to Provisioned IOPS SSD (io1) with a higher IOPS rate.

    Why this is correct

    Provisioned IOPS provides consistent low latency for I/O-intensive workloads.

    Related concept

    Read the scenario before looking for a memorised answer.

Common exam traps

Common exam trap: answer the scenario, not the keyword

The trap here is that candidates often assume Multi-AZ can serve read traffic (like in SQL Server or Oracle), but Amazon RDS for PostgreSQL Multi-AZ does not support read-only queries on the standby; only read replicas can offload reads.

Detailed technical explanation

How to think about this question

Amazon RDS read replicas use asynchronous replication to create a separate read-only endpoint, which offloads read-heavy workloads from the primary instance. Provisioned IOPS (io1) provides a consistent I/O performance with a specified IOPS rate, eliminating the burst-bucket limitations of gp2 that can cause high latency under sustained high read IOPS. In this scenario, the db.r5.large instance has a baseline of 1,500 IOPS for gp2 (3 IOPS per GB), and high read IOPS may exceed the burst balance, causing throttling and increased latency.

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 media company stores terabytes of video archives that are accessed once a year for audit purposes. Moving these objects to a cold storage tier (Azure Archive, S3 Glacier, or Google Nearline) costs a fraction of hot storage. Questions like this test whether you understand storage tiers, access frequency tradeoffs, and retrieval latency requirements.

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.

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FAQ

Questions learners often ask

What does this DBS-C01 question test?

Monitoring and Troubleshooting — This question tests Monitoring and Troubleshooting — Read the scenario before looking for a memorised answer..

What is the correct answer to this question?

The correct answer is: Create a read replica and offload read queries to it. — A is correct because creating a read replica offloads read queries from the primary instance, reducing the read IOPS and read latency on the primary. This directly addresses the high Read Latency and high Read IOPS metrics without requiring a larger instance class or storage change, especially since CPU utilization is low, indicating the bottleneck is I/O, not compute.

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.

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Last reviewed: Jun 11, 2026

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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.