AWS Certified Developer – Associate — Question 246

A company manages a financial services application that stores a large volume of data in an Amazon DynamoDB table. A developer needs to improve the performance of the DynamoDB read queries without increasing the cost.

Which solution meets these requirements?

Answer options

• A. Use parallel scans.
• B. Add a local secondary index (LSI).
• C. Create a DynamoDB Accelerator (DAX) cluster.
• D. Query with the ProjectionExpression parameter.

Correct answer: A

Explanation

Using parallel scans allows simultaneous scanning of multiple segments of a DynamoDB table, which can significantly enhance read query performance without adding costs. In contrast, adding a local secondary index (LSI) or creating a DAX cluster could incur additional costs, and querying with the ProjectionExpression parameter, while efficient, does not directly improve read performance like parallel scans do.