The correct answer is to implement DynamoDB Time to Live (TTL) for automatic deletion of expired items, archive old data to Amazon S3 Glacier using AWS Lambda and DynamoDB Streams, and then query that archived data with Amazon Athena. This combination directly addresses the need to optimize DynamoDB time-series data cost by leveraging TTL to remove stale records without consuming write capacity, while the Lambda-triggered stream captures those expiring items and moves them to Glacier’s ultra-low-cost storage. For rare historical queries, Athena allows you to run SQL directly on the S3 data, avoiding expensive DynamoDB scans. On the AWS Certified Database Specialty exam, this scenario tests your understanding that storage optimization for time-series data is not about adjusting provisioned capacity—increasing RCU or decreasing WCU are traps that either inflate cost or risk throttling. The key insight is to separate hot and cold tiers: keep recent data in DynamoDB for fast writes, then automate the lifecycle to Glacier for cheap retention. Memory tip: think “TTL to Glacier, query with Athena” to remember the three-step pipeline.
DBS-C01 Workload-Specific Database Design Practice Question
This DBS-C01 practice question tests your understanding of workload-specific database design. 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 company runs a time-series application on Amazon DynamoDB. The data has a pattern of frequent writes for recent data and rare reads for older data. They want to optimize storage costs and query performance for the time-series data. Which THREE strategies should they implement? (Choose THREE.)
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Use DynamoDB Time to Live (TTL) to automatically delete old data after a certain period
DynamoDB Time to Live (TTL) automatically deletes expired items, reducing storage. Archiving old data to S3 Glacier provides cheap storage. Using S3 and Athena for historical queries avoids scanning old data in DynamoDB. Option D is wrong because increasing RCU is expensive and not a storage optimization. Option E is wrong because decreasing WCU may cause throttling.
Key principle: NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated.
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 DynamoDB Time to Live (TTL) to automatically delete old data after a certain period
Why this is correct
TTL removes items without consuming WCU and reduces storage costs.
Related concept
Static NAT maps one inside address to one outside address.
✓
Store historical data in Amazon S3 and query with Amazon Athena
Why this is correct
Athena can query S3 data efficiently, offloading old data from DynamoDB.
Related concept
Static NAT maps one inside address to one outside address.
✗
Increase DynamoDB read capacity units to improve query performance
Why it's wrong here
This increases cost and does not optimize storage.
✓
Archive old data to Amazon S3 Glacier using AWS Lambda and DynamoDB Streams
Why this is correct
Archiving to Glacier is cost-effective for rarely accessed data.
Related concept
Static NAT maps one inside address to one outside address.
✗
Decrease DynamoDB write capacity units to reduce cost
Why it's wrong here
Decreasing WCU may cause write throttling; not a strategy for storage optimization.
Common exam traps
Common exam trap: NAT rules depend on direction and matching traffic
NAT is not only about the public address. The inside/outside interface roles and the ACL or rule that matches traffic are just as important.
Detailed technical explanation
How to think about this question
NAT questions usually test address translation, overload/PAT behaviour, static mappings and whether the right traffic is being translated. Read the interface direction and address terms carefully.
KKey Concepts to Remember
Static NAT maps one inside address to one outside address.
PAT allows many inside hosts to share one public address using ports.
Inside local and inside global describe the private and translated addresses.
NAT ACLs identify traffic for translation, not always security filtering.
TExam Day Tips
→Identify inside and outside interfaces first.
→Check whether the scenario needs static NAT, dynamic NAT or PAT.
→Do not confuse NAT matching ACLs with normal packet-filtering intent.
Key takeaway
NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated.
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 the four NAT address types (inside local, inside global, outside local, outside global), PAT port overload, and static vs dynamic NAT use cases. Then practise related DBS-C01 NAT questions on configuration and troubleshooting.
Workload-Specific Database Design — This question tests Workload-Specific Database Design — Static NAT maps one inside address to one outside address..
What is the correct answer to this question?
The correct answer is: Use DynamoDB Time to Live (TTL) to automatically delete old data after a certain period — DynamoDB Time to Live (TTL) automatically deletes expired items, reducing storage. Archiving old data to S3 Glacier provides cheap storage. Using S3 and Athena for historical queries avoids scanning old data in DynamoDB. Option D is wrong because increasing RCU is expensive and not a storage optimization. Option E is wrong because decreasing WCU may cause throttling.
What should I do if I get this DBS-C01 question wrong?
Review the four NAT address types (inside local, inside global, outside local, outside global), PAT port overload, and static vs dynamic NAT use cases. Then practise related DBS-C01 NAT questions on configuration and troubleshooting.
What is the key concept behind this question?
Static NAT maps one inside address to one outside address.
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 →
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.
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.
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.