DBS-C01 Workload-Specific Database Design Practice Question
A company is migrating an on-premises MongoDB database to AWS. The database stores JSON documents for a content management system. The workload requires read-after-write consistency and automatic scaling. Which AWS database service is MOST appropriate?
⚠ Common exam trap
Candidates often choose DynamoDB (Option B) because it is a NoSQL document database with automatic scaling, but they overlook the requirement for MongoDB compatibility and read-after-write consistency, which DynamoDB does not provide by default and requires additional configuration, whereas DocumentDB is purpose-built for MongoDB workloads with strong consistency out of the box.
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 DocumentDB
Amazon DocumentDB is the most appropriate choice because it is a fully managed, MongoDB-compatible document database that natively stores JSON documents, supports read-after-write consistency via its default session consistency model, and provides automatic scaling of storage (up to 64 TB) and compute resources. It directly replaces on-premises MongoDB workloads without requiring schema changes or application rewrites, making it ideal for a content management system.
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 ElastiCache for Redis
Why it's wrong here
ElastiCache is a cache, not a primary database.
- ✗
Amazon DynamoDB
Why it's wrong here
DynamoDB is not MongoDB-compatible; migration would require application changes.
- ✗
Amazon RDS for PostgreSQL
Why it's wrong here
PostgreSQL is relational, not suitable for JSON documents without schema changes.
- ✓
Amazon DocumentDB
Why this is correct
DocumentDB is MongoDB-compatible, provides read-after-write consistency, and scales automatically.
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 1,663 original DBS-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 →
Same concept, more angles
1 more way this is tested on DBS-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 migrating an on-premises MongoDB database to AWS. Which AWS database service is most compatible and requires minimal application changes?
easy- A.Amazon DynamoDB.
- ✓ B.Amazon DocumentDB (with MongoDB compatibility).
- C.Amazon Neptune.
- D.Amazon RDS for MySQL.
Why B: Amazon DocumentDB (with MongoDB compatibility) is the most compatible AWS database service for migrating an on-premises MongoDB database because it is purpose-built to emulate the MongoDB wire protocol and data model, allowing existing MongoDB drivers and tools to connect with minimal or no application code changes. This makes it the ideal choice for a lift-and-shift migration that preserves the document-oriented structure and query patterns of MongoDB.
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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.