- A
Update the CloudFront cache policy to ignore `reqId` and include only the stable `v` query string parameter in the cache key.
Because `reqId` is unique per request, including it in the cache key prevents cache reuse (each request maps to a different cache entry), resulting in frequent origin fetches. Excluding `reqId` and keeping only `v` allows many requests for the same version to share cached objects, reducing origin traffic and cost while preserving correct version behavior.
- B
Lower the CloudFront minimum TTL to 0 seconds so cached objects revalidate more often, reducing origin fetch volume.
Why wrong: Setting TTLs closer to 0 typically increases revalidation/refresh frequency and can increase origin contact. It does not address the root cause here: cache key fragmentation caused by including a unique `reqId` value.
- C
Set the S3 bucket to use compression and enable S3 Transfer Acceleration to reduce origin fetch charges.
Why wrong: The observed increase is driven by higher origin fetch *request* volume caused by poor cache key hit ratio. Compression and Transfer Acceleration may change payload size or transfer characteristics but do not fix the caching failure caused by `reqId` being part of the cache key.
- D
Disable forwarding of the query string to the origin, but keep using the full query string (including `reqId`) in the cache key.
Why wrong: Even if CloudFront does not forward query strings to the origin, the cache key still determines cache reuse. If `reqId` remains part of the cache key, CloudFront will still create mostly unique cache entries, so origin fetches remain high.
SAA-C03 Design Cost-Optimized Architectures Practice Question
This SAA-C03 practice question tests your understanding of design cost-optimized architectures. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. 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 serves versioned images from S3 through CloudFront. After a release, CloudFront origin fetches increased sharply and the monthly CloudFront bill went up. They reviewed CloudFront logs and found that many requests include a query string parameter `reqId` that is unique per request (for example, `...?v=2026-04-01&reqId=...`). The team currently forwards all query strings to the cache key. What change is most likely to reduce origin fetches and cost while keeping the versioned images correct?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue:
"most likely"Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
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
Update the CloudFront cache policy to ignore `reqId` and include only the stable `v` query string parameter in the cache key.
Option A is correct because the `reqId` query string parameter is unique per request, which forces CloudFront to treat each request as a distinct cache object when all query strings are forwarded to the cache key. By configuring the cache policy to include only the stable `v` parameter (the version identifier) and ignore `reqId`, CloudFront can serve cached responses for all requests with the same `v` value, drastically reducing origin fetches and lowering costs. This approach preserves correct versioned image delivery because the `v` parameter still differentiates between image versions.
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.
- ✓
Update the CloudFront cache policy to ignore `reqId` and include only the stable `v` query string parameter in the cache key.
Why this is correct
Because `reqId` is unique per request, including it in the cache key prevents cache reuse (each request maps to a different cache entry), resulting in frequent origin fetches. Excluding `reqId` and keeping only `v` allows many requests for the same version to share cached objects, reducing origin traffic and cost while preserving correct version behavior.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Lower the CloudFront minimum TTL to 0 seconds so cached objects revalidate more often, reducing origin fetch volume.
Why it's wrong here
Setting TTLs closer to 0 typically increases revalidation/refresh frequency and can increase origin contact. It does not address the root cause here: cache key fragmentation caused by including a unique `reqId` value.
- ✗
Set the S3 bucket to use compression and enable S3 Transfer Acceleration to reduce origin fetch charges.
Why it's wrong here
The observed increase is driven by higher origin fetch *request* volume caused by poor cache key hit ratio. Compression and Transfer Acceleration may change payload size or transfer characteristics but do not fix the caching failure caused by `reqId` being part of the cache key.
- ✗
Disable forwarding of the query string to the origin, but keep using the full query string (including `reqId`) in the cache key.
Why it's wrong here
Even if CloudFront does not forward query strings to the origin, the cache key still determines cache reuse. If `reqId` remains part of the cache key, CloudFront will still create mostly unique cache entries, so origin fetches remain high.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates may think forwarding all query strings is harmless or that lowering TTL helps reduce origin fetches, but the real issue is cache key fragmentation caused by unique parameters like `reqId`.
Detailed technical explanation
How to think about this question
CloudFront cache keys are built from the request URL, including query strings when forwarding is enabled. By default, CloudFront includes all query string parameters in the cache key unless a cache policy explicitly whitelists or ignores specific parameters. The `reqId` parameter, being unique per request, creates a new cache entry for every request, leading to cache misses and origin fetches. In contrast, the `v` parameter is stable across requests for the same image version, so whitelisting only `v` ensures cache hits for all requests with the same version, while ignoring `reqId` prevents cache fragmentation. This is a common pattern for versioned static assets served through CDNs.
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 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.
Quick reference
AWS S3 Storage Class Comparison
| Storage Class | Min Duration | Retrieval | Use Case |
|---|---|---|---|
| S3 Standard | None | Immediate | Frequently accessed data |
| S3 Standard-IA | 30 days | Immediate | Infrequent access, rapid retrieval |
| S3 One Zone-IA | 30 days | Immediate | Non-critical infrequent data |
| S3 Intelligent-Tiering | None | Immediate–hours | Unknown or changing access patterns |
| S3 Glacier Instant | 90 days | Milliseconds | Archive with instant retrieval |
| S3 Glacier Flexible | 90 days | Minutes–hours | Archive, flexible retrieval |
| S3 Glacier Deep Archive | 180 days | Hours | Long-term compliance archive |
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.
- →
Design Cost-Optimized Architectures — study guide chapter
Learn the concepts, then practise the questions
- →
Design Cost-Optimized Architectures practice questions
Targeted practice on this topic area only
- →
All SAA-C03 questions
1,040 questions across all exam domains
- →
SAA-C03 study guide
Full concept coverage aligned to exam objectives
- →
SAA-C03 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related SAA-C03 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Design Secure Architectures practice questions
Practise SAA-C03 questions linked to Design Secure Architectures.
Design Resilient Architectures practice questions
Practise SAA-C03 questions linked to Design Resilient Architectures.
Design High-Performing Architectures practice questions
Practise SAA-C03 questions linked to Design High-Performing Architectures.
Design Cost-Optimized Architectures practice questions
Practise SAA-C03 questions linked to Design Cost-Optimized Architectures.
SAA-C03 VPC practice questions
Practise SAA-C03 questions linked to SAA-C03 VPC.
SAA-C03 S3 lifecycle policy questions
Practise SAA-C03 questions linked to SAA-C03 S3 lifecycle policy questions.
SAA-C03 RDS Multi-AZ questions
Practise SAA-C03 questions linked to SAA-C03 RDS Multi-AZ questions.
SAA-C03 IAM policy practice questions
Practise SAA-C03 questions linked to SAA-C03 IAM policy.
SAA-C03 Route 53 failover questions
Practise SAA-C03 questions linked to SAA-C03 Route 53 failover questions.
SAA-C03 CloudFront practice questions
Practise SAA-C03 questions linked to SAA-C03 CloudFront.
SAA-C03 NAT gateway questions
Practise SAA-C03 questions linked to SAA-C03 NAT gateway questions.
SAA-C03 VPC endpoint questions
Practise SAA-C03 questions linked to SAA-C03 VPC endpoint questions.
Practice this exam
Start a free SAA-C03 practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this SAA-C03 question test?
Design Cost-Optimized Architectures — This question tests Design Cost-Optimized Architectures — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Update the CloudFront cache policy to ignore `reqId` and include only the stable `v` query string parameter in the cache key. — Option A is correct because the `reqId` query string parameter is unique per request, which forces CloudFront to treat each request as a distinct cache object when all query strings are forwarded to the cache key. By configuring the cache policy to include only the stable `v` parameter (the version identifier) and ignore `reqId`, CloudFront can serve cached responses for all requests with the same `v` value, drastically reducing origin fetches and lowering costs. This approach preserves correct versioned image delivery because the `v` parameter still differentiates between image versions.
What should I do if I get this SAA-C03 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
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 →
Keep practising
More SAA-C03 practice questions
- A content publishing system uses Lambda functions that call an unreliable third-party API. Failed events must be retaine…
- A startup runs two EC2-based workloads in the same AWS Region. Its customer-facing API is always on, and its nightly vid…
- A warehouse integration service must use shared file storage across Linux EC2 instances in multiple Availability Zones.…
- A team runs a stateless web app on Amazon EC2 behind an Application Load Balancer. During traffic spikes, new EC2 instan…
- A service in private subnets downloads product images from Amazon S3 and stores job state in DynamoDB. A NAT Gateway is…
- A static site is hosted in Amazon S3 and delivered by CloudFront. After a frontend release, the same JavaScript bundles…
Last reviewed: Jun 11, 2026
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.
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.
Sign in to join the discussion.