DVA-C02 Development with AWS Services Practice Question
A developer is using Amazon DynamoDB as the data store for a serverless application. The application experiences high read traffic, and the developer wants to reduce latency. The data is not frequently updated. Which DynamoDB feature should the developer use?
⚠ Common exam trap
A common mix-up: candidates confuse DAX with Global Tables, thinking that replicating data across regions reduces latency, but the question specifies reducing latency within a single region, where DAX's in-memory caching is the correct solution.
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
✓
DynamoDB Accelerator (DAX)
DynamoDB Accelerator (DAX) is a fully managed, in-memory cache that reduces read latency for DynamoDB tables from single-digit milliseconds to microseconds. Since the data is not frequently updated, DAX can serve repeated read requests from its cache without hitting the underlying table, making it ideal for high-read, low-write workloads.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
DynamoDB Auto Scaling
Why it's wrong here
DynamoDB Auto Scaling automatically adjusts the provisioned read and write capacity units (RCUs/WCUs) of a DynamoDB table in response to actual traffic patterns. While this prevents throttling errors due to insufficient capacity, it does not inherently reduce the latency of individual read operations from the underlying DynamoDB storage. Auto Scaling ensures the availability of capacity, not the speed of data retrieval for a given request.
- ✗
DynamoDB Global Tables
Why it's wrong here
DynamoDB Global Tables provide a fully managed, multi-region, active-active replication solution for DynamoDB tables. They enable applications to access data from the closest replica, reducing network latency for geographically distributed users and enhancing disaster recovery capabilities. However, Global Tables do not implement an in-memory caching layer to accelerate read operations from the primary data store itself, which is the specific function required for microsecond-latency reads.
- ✓
DynamoDB Accelerator (DAX)
Why this is correct
DynamoDB Accelerator (DAX) is a fully managed, highly available, in-memory cache specifically designed for DynamoDB. It provides microsecond response times for read-heavy workloads by caching items and query results, significantly reducing the load on the underlying DynamoDB table. DAX acts as a transparent proxy, allowing applications to continue using the DynamoDB API while benefiting from accelerated read performance.
- ✗
DynamoDB Time to Live (TTL)
Why it's wrong here
DynamoDB Time to Live (TTL) is a feature that allows you to define a timestamp attribute on your items, after which DynamoDB automatically deletes them from the table. This is primarily used for managing data lifecycle, reducing storage costs, and ensuring data compliance by expiring old or irrelevant data. TTL does not provide any caching mechanism or performance enhancement for read latency; it is a data management utility.
Quick reference
Cloud Service Model Comparison
| Model | You Manage | Provider Manages | Examples |
|---|---|---|---|
| IaaS | OS, runtime, apps, data | Hardware, hypervisor, networking | EC2, Azure VMs, GCP Compute Engine |
| PaaS | Apps and data | OS, runtime, middleware, hardware | Elastic Beanstalk, Azure App Service |
| SaaS | Data and settings only | Everything else | Microsoft 365, Salesforce, Workday |
| FaaS / Serverless | Function code only | Infra, scaling, runtime | Lambda, Azure Functions, Cloud Run |
| CaaS | Containers and apps | Kubernetes, OS, hardware | EKS, AKS, GKE |
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This DVA-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 DVA-C02 exam.