Question 677 of 1,040
Design Cost-Optimized ArchitectureshardMultiple SelectObjective-mapped

Quick Answer

The answer is to use DynamoDB on-demand capacity for the shopping-cart profile store and Aurora Serverless v2 for the relational database. This combination is correct because both services automatically scale compute capacity based on actual demand, eliminating the need to provision for peak traffic and ensuring you only pay for resources consumed, which is the core of a cost-optimized database for unpredictable traffic. On the SAA-C03 exam, this scenario tests your understanding of serverless versus provisioned capacity models, often appearing in questions about minimizing costs for spiky or unknown workloads. A common trap is selecting DynamoDB provisioned capacity or standard Aurora, which would leave you paying for idle resources. Remember the key principle: unpredictable traffic demands serverless scaling. For a quick memory tip, think “Serverless for Surges”—when traffic is unpredictable, choose services that scale to zero and charge per use, not per provisioned slot.

SAA-C03 Design Cost-Optimized Architectures Practice Question

This SAA-C03 practice question tests your understanding of design cost-optimized architectures. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. A key principle to apply: aurora Serverless v2 scales compute and memory automatically.. 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 product catalog system uses a relational database for orders and a simple key-value profile store for shopping carts. Traffic is unpredictable, and the company wants to avoid paying for large idle database instances. Which two choices are best? Select two.

Clue words in this question

Noticing these words before you look at the options changes how you read each choice.

  • Clue: "best"

    Why it matters: Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.

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

Use Aurora Serverless v2 for the relational order system.

Aurora Serverless v2 automatically scales compute capacity up and down based on demand, so you only pay for the resources you use. This eliminates the need to provision for peak traffic and avoids paying for large idle database instances, making it cost-optimized for unpredictable workloads.

Key principle: Aurora Serverless v2 scales compute and memory automatically.

Answer analysis

Option-by-option breakdown

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

  • Use Aurora Serverless v2 for the relational order system.

    Why this is correct

    Correct. Aurora Serverless v2 is designed for variable relational workloads because capacity can scale without constantly paying for a large fixed instance. It preserves SQL features while reducing idle overprovisioning.

    Clue confirmation

    The clue word "best" in the question point toward this answer.

    Related concept

    Aurora Serverless v2 scales compute and memory automatically.

  • Use DynamoDB on-demand capacity for the shopping-cart profile store.

    Why this is correct

    Correct. On-demand capacity fits unpredictable key-value traffic and avoids the need to guess throughput in advance. It is a strong cost choice when access patterns are variable and the schema is simple.

    Clue confirmation

    The clue word "best" in the question point toward this answer.

    Related concept

    Aurora Serverless v2 scales compute and memory automatically.

  • Keep both workloads on large provisioned RDS instances and add read replicas for the cart store.

    Why it's wrong here

    Incorrect. This keeps both systems on fixed-capacity relational infrastructure even where a simpler managed database would be cheaper. The cart workload does not justify expensive relational replicas.

  • Use DynamoDB provisioned capacity with a fixed minimum despite the unpredictable traffic.

    Why it's wrong here

    Incorrect. Fixed provisioned capacity can be cheaper only when traffic is stable and predictable. Here, the company explicitly wants to avoid paying for idle capacity during variable demand.

  • Replace the relational order system with a wide-column table to reduce SQL licensing.

    Why it's wrong here

    Incorrect. Replacing the relational system would force a redesign and remove the SQL and transaction model that order processing usually needs. Cost optimization should not break the application requirements.

Common exam traps

Common exam trap: answer the scenario, not the keyword

The trap here is that candidates may think provisioned capacity with a minimum is acceptable for unpredictable traffic, but the question explicitly requires avoiding paying for idle capacity, so on-demand or serverless options are the only correct choices.

Detailed technical explanation

How to think about this question

Aurora Serverless v2 uses a shared storage volume and scales in increments of 0.5 ACU (Aurora Capacity Units), allowing fine-grained scaling from 0.5 to 128 ACUs per instance. DynamoDB on-demand capacity automatically scales to handle up to double the previous peak traffic within minutes, and you pay per request (read/write units) with no minimum commitment, making it ideal for spiky, unpredictable workloads like shopping carts.

KKey Concepts to Remember

  • Aurora Serverless v2 scales compute and memory automatically.
  • Aurora Serverless v2 bills for actual consumption, not provisioned capacity.
  • DynamoDB on-demand capacity scales throughput automatically.
  • DynamoDB on-demand is ideal for unpredictable NoSQL workloads.

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

Aurora Serverless v2 scales compute and memory automatically.

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 aurora Serverless v2 scales compute and memory automatically., then practise related SAA-C03 questions on the same topic to reinforce the concept.

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FAQ

Questions learners often ask

What does this SAA-C03 question test?

Design Cost-Optimized Architectures — This question tests Design Cost-Optimized Architectures — Aurora Serverless v2 scales compute and memory automatically..

What is the correct answer to this question?

The correct answer is: Use Aurora Serverless v2 for the relational order system. — Aurora Serverless v2 automatically scales compute capacity up and down based on demand, so you only pay for the resources you use. This eliminates the need to provision for peak traffic and avoids paying for large idle database instances, making it cost-optimized for unpredictable workloads.

What should I do if I get this SAA-C03 question wrong?

Review aurora Serverless v2 scales compute and memory automatically., then practise related SAA-C03 questions on the same topic to reinforce the concept.

Are there clue words in this question I should notice?

Yes — watch for: "best". Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.

What is the key concept behind this question?

Aurora Serverless v2 scales compute and memory automatically.

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Last reviewed: Jun 11, 2026

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This SAA-C03 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 SAA-C03 exam.