AWS Certified Solutions Architect – Professional (SAP-C02) — Question 282

A financial services company loaded millions of historical stock trades into an Amazon DynamoDB table. The table uses on-demand capacity mode. Once each day at midnight, a few million new records are loaded into the table. Application read activity against the table happens in bursts throughout the day. and a limited set of keys are repeatedly looked up. The company needs to reduce costs associated with DynamoDB.

Which strategy should a solutions architect recommend to meet this requirement?

Answer options

• A. Deploy an Amazon ElastiCache cluster in front of the DynamoDB table
• B. Deploy DynamoDB Accelerator (DAX). Configure DynamoDB auto scaling. Purchase Savings Plans in Cost Explorer.
• C. Use provisioned capacity mode. Purchase Savings Plans in Cost Explorer.
• D. Deploy DynamoDB Accelerator (DAX). Use provisioned capacity mode. Configure DynamoDB auto scaling.

Correct answer: D

Explanation

Implementing DynamoDB Accelerator (DAX) caches the frequently repeated read requests, which significantly lowers read costs and latency. Switching from on-demand to provisioned capacity mode combined with auto scaling accommodates the predictable daily batch load and read bursts far more cost-effectively. Other options are incorrect because ElastiCache requires complex application-level integration compared to DAX, and AWS Savings Plans do not apply to DynamoDB resource costs.