AWS Certified Solutions Architect – Associate (SAA-C03) — Question 483

A company is designing a new web application that will run on Amazon EC2 Instances. The application will use Amazon DynamoDB for backend data storage. The application traffic will be unpredictable. The company expects that the application read and write throughput to the database will be moderate to high. The company needs to scale in response to application traffic.

Which DynamoDB table configuration will meet these requirements MOST cost-effectively?

Answer options

• A. Configure DynamoDB with provisioned read and write by using the DynamoDB Standard table class. Set DynamoDB auto scaling to a maximum defined capacity.
• B. Configure DynamoDB in on-demand mode by using the DynamoDB Standard table class.
• C. Configure DynamoDB with provisioned read and write by using the DynamoDB Standard Infrequent Access (DynamoDB Standard-IA) table class. Set DynamoDB auto scaling to a maximum defined capacity.
• D. Configure DynamoDB in on-demand mode by using the DynamoDB Standard Infrequent Access (DynamoDB Standard-IA) table class.

Correct answer: B

Explanation

On-demand capacity mode is ideal for unpredictable workloads because it scales instantly to accommodate sudden traffic spikes without requiring capacity planning. The DynamoDB Standard table class is the most cost-effective choice here because the application has moderate-to-high read/write throughput, whereas the DynamoDB Standard-IA class is optimized for tables where storage is the primary cost and data access is infrequent.