Quick Answer
Amazon DocumentDB is the correct choice because it is a fully managed, MongoDB-compatible document database designed for JSON document workloads like content management systems, offering both read-after-write consistency through its default session consistency model and automatic scaling of storage up to 64 TB. This makes it the most appropriate service for migrating an on-premises MongoDB database to AWS without requiring schema changes or application rewrites. On the AWS Certified Database Specialty DBS-C01 exam, this scenario tests your ability to match workload characteristics—specifically JSON storage, read-after-write consistency, and auto-scaling—to the correct purpose-built database, with a common trap being to confuse DocumentDB with DynamoDB (which lacks native MongoDB compatibility and read-after-write consistency by default). Remember the memory tip: "DocumentDB for documents, DynamoDB for key-value"—if the workload stores JSON natively and needs MongoDB compatibility, DocumentDB is your answer.
This DBS-C01 practice question tests your understanding of workload-specific database design. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. 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 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?
Amazon ElastiCache for Redis
Why wrong: ElastiCache is a cache, not a primary database.
Amazon DynamoDB
Why wrong: DynamoDB is not MongoDB-compatible; migration would require application changes.
Amazon RDS for PostgreSQL
Why wrong: PostgreSQL is relational, not suitable for JSON documents without schema changes.
Amazon DocumentDB
DocumentDB is MongoDB-compatible, provides read-after-write consistency, and scales automatically.
Answer choices
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.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
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.
Related concept
Read the scenario before looking for a memorised answer.
Common exam traps
The trap here is that 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.
Detailed technical explanation
Amazon DocumentDB implements the MongoDB 3.6 and 4.0 wire protocols, allowing existing MongoDB drivers and tools to connect without changes, and it uses a distributed storage volume that replicates data across three Availability Zones (AZs) with 6 copies, ensuring read-after-write consistency by default for all reads within the same session. Under the hood, DocumentDB separates compute and storage, enabling automatic storage scaling in 10 GB increments up to 64 TB, while compute scaling can be done via instance resizing with minimal downtime, which is critical for content management systems with unpredictable growth.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
A media company stores terabytes of video archives that are accessed once a year for audit purposes. Moving these objects to a cold storage tier (Azure Archive, S3 Glacier, or Google Nearline) costs a fraction of hot storage. Questions like this test whether you understand storage tiers, access frequency tradeoffs, and retrieval latency requirements.
What to study next
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Workload-Specific Database Design — study guide chapter
Learn the concepts, then practise the questions
Workload-Specific Database Design practice questions
Targeted practice on this topic area only
All DBS-C01 questions
1,730 questions across all exam domains
AWS Certified Database Specialty DBS-C01 study guide
Full concept coverage aligned to exam objectives
DBS-C01 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Practise DBS-C01 questions linked to Workload-Specific Database Design.
Practise DBS-C01 questions linked to Deployment and Migration.
Practise DBS-C01 questions linked to Management and Operations.
Practise DBS-C01 questions linked to Monitoring and Troubleshooting.
Practise DBS-C01 questions linked to Database Security.
Practise DBS-C01 questions linked to DBS-C01 fundamentals.
Practise DBS-C01 questions linked to DBS-C01 scenario.
Practise DBS-C01 questions linked to DBS-C01 troubleshooting.
Practice this exam
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Workload-Specific Database Design — This question tests Workload-Specific Database Design — Read the scenario before looking for a memorised answer..
The correct answer is: 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.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Read the scenario before looking for a memorised answer.
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 →
Same concept, more angles
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?
easyWhy 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.
Last reviewed: Jun 24, 2026
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.