DEA-C01 Data Store Management Practice Question
A data engineer is designing a data lake on Amazon S3. The data is accessed frequently for the first 30 days, then rarely after that. Compliance requires that data be retained for 7 years. What is the MOST cost-effective storage strategy?
⚠ Common exam trap
AWS often tests the misconception that S3 Intelligent-Tiering is always the most cost-effective for unknown access patterns, but in this scenario with a known access pattern (frequent for 30 days, then rarely), a lifecycle policy with explicit transitions is cheaper because it avoids the per-object monitoring fee of Intelligent-Tiering.
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 S3 Standard for 30 days, then transition to S3 Standard-IA, then to S3 Glacier Deep Archive after 90 days.
The most cost-effective because it matches the access pattern: S3 Standard for the first 30 days of frequent access, then S3 Standard-IA for the next 60 days (reduced storage cost with a retrieval fee), and finally S3 Glacier Deep Archive for the remaining ~6.9 years to meet the 7-year retention requirement at the lowest possible storage cost. This lifecycle policy minimizes total cost by transitioning data to progressively cheaper storage tiers as access frequency drops, while still meeting compliance.
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 S3 Intelligent-Tiering for the entire 7 years.
Why it's wrong here
Intelligent-Tiering has monitoring and automation costs that may not be optimal.
- ✗
Store all data in S3 Standard for 7 years.
Why it's wrong here
Standard is expensive for data accessed rarely after 30 days.
- ✗
Use S3 Standard for 30 days, then S3 One Zone-IA for 7 years.
Why it's wrong here
One Zone-IA is not durable enough for compliance.
- ✓
Use S3 Standard for 30 days, then transition to S3 Standard-IA, then to S3 Glacier Deep Archive after 90 days.
Why this is correct
Standard-IA for infrequent access, then Glacier Deep Archive for long-term retention.
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 |
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Same concept, more angles
2 more ways this is tested on DEA-C01
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A company is storing large amounts of log data in Amazon S3. The data is accessed frequently for the first 30 days, then rarely after that. The company wants to automatically transition the data to a lower-cost storage class after 30 days. Which S3 feature should the data engineer use?
easy- A.S3 Intelligent-Tiering
- ✓ B.S3 Lifecycle policies
- C.S3 Cross-Region Replication
- D.S3 Batch Operations
Why B: S3 Lifecycle policies allow you to define rules that automatically transition objects between storage classes based on age or other criteria. In this scenario, a lifecycle rule can be configured to transition objects from S3 Standard to a lower-cost class like S3 Glacier Deep Archive after 30 days, directly meeting the requirement for automated cost optimization.
Variation 2. A company stores its application logs in an Amazon S3 bucket. The logs are accessed frequently for the first 30 days, after which they are rarely accessed but must be retained for 7 years for compliance. The company wants to optimize storage costs while maintaining immediate retrieval availability for the first 30 days and the ability to retrieve logs within 12 hours after that. Which lifecycle policy should the data engineer configure?
easy- A.Delete objects after 30 days to minimize storage costs.
- ✓ B.Transition objects to S3 Standard-IA after 30 days and then to S3 Glacier Deep Archive after 1 year.
- C.Transition objects to S3 One Zone-IA after 30 days and delete after 7 years.
- D.Transition objects to S3 Glacier Flexible Retrieval after 30 days and delete after 7 years.
Why B: It uses S3 Standard-IA for the first 30 days (frequent access, immediate retrieval) and then transitions to S3 Glacier Deep Archive after 1 year, which provides retrieval within 12 hours at the lowest cost for long-term retention. This meets the compliance requirement of 7-year retention while optimizing costs by moving data to progressively cheaper storage classes based on access patterns.
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This DEA-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 DEA-C01 exam.