AWS Certified Developer – Associate — Question 259

A developer has an Amazon DynamoDB table that must be in provisioned mode to comply with user requirements. The application needs to support the following:

• Average item size: 10 KB
• Item reads each second: 10 strongly consistent
• Item writes each second: 2 transactional

Which read and write capacity cost-effectively meets these requirements?

Answer options

• A. Read 10; write 2
• B. Read 30; write 40
• C. Use on-demand scaling
• D. Read 300; write 400

Correct answer: B

Explanation

The correct answer is B because, for strongly consistent reads, the table requires 3 read capacity units per second per item (10 KB item size), totaling 30 units for 10 reads. For transactional writes, the table needs 20 write capacity units for 2 transactional writes per second (10 KB item size each). Options A, C, and D do not meet the requirements effectively in comparison to option B.