The answer is the need for complex joins and relationships. This is correct because Amazon RDS supports relational databases with full SQL capabilities, including JOIN operations, foreign keys, and ACID transactions, whereas DynamoDB is a NoSQL key-value and document store designed for high-scale, low-latency access without native support for complex relational queries. On the AWS Certified Database Specialty DBS-C01 exam, this factor tests your ability to match workload patterns to the right service: choose RDS when your application requires normalized schemas and multi-table relationships, and DynamoDB when you need flexible, denormalized schemas with single-table design. A common trap is assuming DynamoDB can handle complex joins through application logic, but the exam emphasizes that native relational features are a core differentiator. Remember the mnemonic “RDS for Relations, Dynamo for Denormalization” to quickly recall that complex joins point to RDS.
DBS-C01 Workload-Specific Database Design Practice Question
This DBS-C01 practice question tests your understanding of workload-specific database design. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. 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.
Which THREE are factors to consider when choosing between Amazon RDS and Amazon DynamoDB? (Select THREE.)
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Serverless capacity management
Option A is correct because Amazon RDS requires manual or auto-scaling of compute and storage capacity, while DynamoDB offers serverless capacity management with on-demand mode that automatically scales throughput based on traffic. This is a key differentiator when deciding between provisioned capacity (RDS) and fully managed, pay-per-request scaling (DynamoDB).
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✓
Serverless capacity management
Why this is correct
DynamoDB is serverless; RDS requires provisioning.
Related concept
Read the scenario before looking for a memorised answer.
✓
ACID transaction support across multiple tables
Why this is correct
RDS supports ACID across tables; DynamoDB supports only single-table transactions.
Related concept
Read the scenario before looking for a memorised answer.
✓
Need for complex joins and relationships
Why this is correct
RDS supports joins; DynamoDB does not.
Related concept
Read the scenario before looking for a memorised answer.
Neither is an in-memory cache; both can be used with ElastiCache.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates may think encryption at rest or in-memory caching are exclusive to one service, but AWS offers these features across both RDS and DynamoDB, making them irrelevant for choosing between the two.
Detailed technical explanation
How to think about this question
DynamoDB uses a distributed hash table architecture that partitions data across multiple nodes, making it inherently serverless and horizontally scalable. In contrast, RDS is a relational database that runs on a single instance (or a Multi-AZ replica), requiring explicit scaling of instance size or storage. The choice between them often hinges on whether the workload requires complex relational queries (RDS) or simple key-value and document access patterns with automatic scaling (DynamoDB).
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
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
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Workload-Specific Database Design — This question tests Workload-Specific Database Design — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Serverless capacity management — Option A is correct because Amazon RDS requires manual or auto-scaling of compute and storage capacity, while DynamoDB offers serverless capacity management with on-demand mode that automatically scales throughput based on traffic. This is a key differentiator when deciding between provisioned capacity (RDS) and fully managed, pay-per-request scaling (DynamoDB).
What should I do if I get this DBS-C01 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
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 →
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. Which TWO factors should you consider when choosing between Amazon RDS and Amazon DynamoDB for a new application?
medium
✓ A.RDS requires a predefined schema, while DynamoDB is schema-less.
B.DynamoDB can only be accessed from within a VPC, while RDS can be public.
C.Only RDS supports Multi-AZ deployments for high availability.
D.Both services support encryption at rest and in transit.
✓ E.DynamoDB is better suited for unstructured data, while RDS is better for structured data with complex relationships.
Why A: Option B is correct because DynamoDB uses a NoSQL model, while RDS uses relational. Option E is correct because DynamoDB supports flexible schema, while RDS requires fixed schema. Option A is wrong because both support encryption. Option C is wrong because both support VPC. Option D is wrong because both support multi-AZ deployments (RDS Multi-AZ, DynamoDB global tables).
Variation 2. Which TWO factors should be considered when choosing between Amazon DynamoDB and Amazon RDS for MySQL for a new e-commerce application with variable traffic patterns?
medium
A.Ability to perform complex joins and aggregations: DynamoDB supports SQL-like queries.
✓ B.Operational overhead: DynamoDB is serverless, RDS requires patching and provisioning.
C.Support for ACID transactions in both databases.
D.Encryption at rest is only available for RDS.
✓ E.Automatic scaling of throughput with DynamoDB on-demand vs. manual scaling of RDS.
Why B: Option B is correct because DynamoDB is a fully managed serverless service that eliminates the need for patching, provisioning, or managing servers, whereas Amazon RDS for MySQL requires manual patching, scaling, and instance provisioning. This operational overhead difference is critical for variable traffic patterns, as DynamoDB automatically handles infrastructure management, reducing administrative burden.
Last reviewed: Jun 24, 2026
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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.
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