Question 742 of 1,711
DEA-C01 Data Store Management Practice Question
A data engineer needs to store semi-structured JSON data from IoT devices. The data is written once, read rarely, but must be queryable using SQL. The storage cost must be minimized. Which storage solution should the engineer choose?
⚠ Common exam trap
Test-takers frequently choose DynamoDB (Option C) because it supports JSON natively and PartiQL provides SQL-like queries, but they overlook that DynamoDB's provisioned throughput and storage costs are significantly higher than S3 for write-once, read-rarely workloads, and that Athena on S3 is the serverless, cost-optimized solution for ad-hoc SQL queries on infrequently accessed data.
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
✓
Store JSON files in Amazon S3 and use Amazon Athena for queries
Amazon S3 provides the lowest-cost storage for data that is written once and rarely read, while Amazon Athena enables serverless SQL querying directly on JSON files stored in S3. This combination minimizes storage costs because S3 charges only for the data stored and retrieval, with no minimum fees or provisioning required, and Athena charges only for the data scanned per query. The workload's write-once, read-rarely pattern aligns perfectly with S3's durability and lifecycle policies, making it the most cost-effective choice.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Store JSON in Amazon Redshift as SUPER data type
Why it's wrong here
Redshift is for analytics and has higher storage cost than S3.
- ✗
Store JSON in an Amazon RDS for MySQL table
Why it's wrong here
RDS storage costs more than S3 and requires schema management.
- ✗
Store JSON documents in Amazon DynamoDB and use PartiQL for queries
Why it's wrong here
DynamoDB is optimized for frequent access; cost per GB is higher than S3.
- ✓
Store JSON files in Amazon S3 and use Amazon Athena for queries
Why this is correct
S3 provides low-cost storage; Athena enables SQL querying over JSON.
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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Last reviewed: Jun 24, 2026
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.
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