SAP-C02 Design for New Solutions Practice Question
A company is designing a new application that will use Amazon DynamoDB. The application requires strongly consistent reads and must handle a sudden spike in read traffic that could exceed the provisioned read capacity. The company wants to ensure that the application continues to perform well without manual intervention. The table is currently provisioned with 100 read capacity units (RCUs). The workload is unpredictable but expected to grow. What should a solutions architect recommend to meet these requirements?
⚠ Common exam trap
The trap here is assuming that DAX can be used with strongly consistent reads, when in fact DAX only supports eventually consistent reads, making it unsuitable for this scenario.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Switch the table to on-demand capacity mode.
DynamoDB on-demand capacity mode is designed for unpredictable workloads and automatically scales read and write capacity to handle traffic spikes without manual intervention. It supports strongly consistent reads, so it meets the consistency requirement. This mode eliminates the need to provision or manage capacity, providing seamless performance during sudden spikes.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Enable DynamoDB Accelerator (DAX) for the table and use strongly consistent reads.
Why it's wrong here
DAX does not support strongly consistent reads; it only supports eventually consistent reads. Enabling DAX would not meet the strong consistency requirement. While DAX can improve read performance, it is not suitable here because of the consistency model, making this option incorrect.
- ✗
Increase the provisioned read capacity to a high fixed value, such as 10,000 RCUs, and enable auto scaling.
Why it's wrong here
While auto scaling can adjust capacity, it reacts to CloudWatch metrics and may not respond instantly to sudden spikes, leading to throttling. Setting a high fixed value increases cost and still may not handle unpredictable spikes. This option does not provide the same seamless scaling as on-demand mode.
- ✗
Create a global secondary index (GSI) with eventually consistent reads and direct read traffic to the GSI.
Why it's wrong here
GSIs only support eventually consistent reads, not strongly consistent reads. Directing traffic to a GSI would violate the strong consistency requirement. Additionally, a GSI does not solve the capacity spike issue; it has its own capacity settings. This option fails both the consistency and scaling requirements.
- ✓
Switch the table to on-demand capacity mode.
Why this is correct
On-demand capacity mode automatically scales to handle sudden spikes in traffic without manual intervention. It supports strongly consistent reads, and you pay per request. This meets the requirements for unpredictable workloads and eliminates the need to manage capacity, ensuring performance during spikes.
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Amazon Web Services exam blueprint
This SAP-C02 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the SAP-C02 exam.