DEA-C01 Data Store Management Practice Question
A company needs to store relational data that requires complex joins and transactional consistency. The workload is predictable and the data size is less than 500 GB. Which AWS service is MOST cost-effective for this use case?
⚠ Common exam trap
A common mix-up: candidates choose Amazon Redshift for any data that involves joins or analytics, ignoring that it is cost-prohibitive and architecturally mismatched for transactional, sub-500 GB workloads, while RDS is the correct relational database service for this scale.
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
✓
Amazon RDS for PostgreSQL
Amazon RDS for PostgreSQL is the most cost-effective choice because it provides a fully managed relational database service that supports complex joins and transactional consistency (ACID compliance) for predictable workloads under 500 GB. Unlike Redshift, which is optimized for petabyte-scale analytics, RDS offers lower cost for this data size and workload pattern, while DynamoDB lacks native SQL join capabilities and S3 is not a relational database.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Amazon Redshift
Why it's wrong here
Redshift is a data warehouse optimized for large-scale analytics, not cost-effective for sub-500 GB relational data.
- ✗
Amazon S3
Why it's wrong here
S3 is object storage, not a relational database; it cannot perform joins or transactions.
- ✓
Amazon RDS for PostgreSQL
Why this is correct
RDS offers managed relational databases with full SQL support, ideal for transactional workloads up to 500 GB.
- ✗
Amazon DynamoDB
Why it's wrong here
DynamoDB is NoSQL and does not support complex joins or transactions across multiple tables.
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 |
Go deeper
Related to this question
About these practice questions
One of 1,711 original DEA-C01 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
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.