These questions are independently created for study purposes. They are not official AWS exam questions, actual exam questions, leaked questions, or exam dumps.
CLF-021
Which of the following best describes Amazon DynamoDB?
Choices
Explanation and answer
Read the explanation and correct answer (spoiler — try answering first)
Correct answer: B. A fully managed NoSQL database service
Explanation
Amazon DynamoDB is a fully managed NoSQL database service that is well suited for storing key-value and document data.
Per-choice explanations
A. A CDN that delivers only static files
Incorrect. The CDN service is CloudFront.
B. A fully managed NoSQL database service
Correct. DynamoDB is a fully managed NoSQL database.
C. A service for launching virtual servers
Incorrect. Virtual servers are provided by EC2.
D. A service for creating virtual networks
Incorrect. Virtual networks are provided by VPC.
Practical Use
Amazon DynamoDB is a fully managed NoSQL database service provided by AWS. In the CLF-C02 exam context, the key is to use it as a binary decision axis: "does the workload need a relational database, or does it need NoSQL?" The DynamoDB characteristics that appear on the exam can be summarized into four points. (1) It is NoSQL (schemaless and non-relational). (2) It is fully managed, so no server administration is required and scaling is handled automatically. (3) It is designed for high throughput and single-digit millisecond latency. (4) It is commonly used as the backend of serverless architectures together with Lambda and API Gateway. As a decision axis, use RDS when an existing relational schema and JOIN operations are required, and use DynamoDB when access patterns are simple and large volumes of reads and writes are needed, or when the system is designed around NoSQL access patterns. On the CLF exam, DynamoDB is the correct answer to questions such as "Which is the managed NoSQL key-value service?" and "Which database is used with Lambda for a serverless architecture?" Common distractors include RDS (relational database), VPC (virtual network), EC2 (virtual server), and CloudFront (CDN).