AWS Certified Developer – Associate — Question 353

A developer is creating a new application for a pet store. The application will manage customer rewards points. The developer will use Amazon DynamoDB to store the data for the application. The developer needs to optimize query performance and limit partition overload before actual performance analysis.

Which option should the developer use for a partition key to meet these requirements?

Answer options

• A. A randomly generated universally unique identifier (UUID)
• B. The customer’s full name
• C. The date when the customer signed up for the rewards program
• D. The name of the customer’s pet

Correct answer: A

Explanation

A randomly generated UUID has high cardinality, which ensures that write and read requests are evenly distributed across all DynamoDB partitions, preventing hot partitions. Attributes like sign-up dates, pet names, or full names have lower cardinality and can lead to uneven data distribution and partition overload. Therefore, using a unique, randomized identifier is the best practice for optimal partition key design in DynamoDB.