DP-203 Design and implement data storage Practice Question
A data engineer needs to store semi-structured JSON logs from IoT devices. The data will be queried using SQL and must support high-throughput writes. Which Azure data store is most appropriate?
⚠ Common exam trap
Many exam-takers choose Azure Blob Storage or Data Lake Storage because they associate JSON files with cheap storage, but they overlook the requirement for high-throughput writes and native SQL querying, which Cosmos DB uniquely satisfies among the options.
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
✓
Azure Cosmos DB with Core (SQL) API
Azure Cosmos DB with Core (SQL) API is the most appropriate choice because it natively stores semi-structured JSON documents, supports high-throughput writes with single-digit millisecond latency, and allows querying the JSON data directly using SQL syntax. Its schema-agnostic design and automatic indexing make it ideal for IoT workloads where device telemetry arrives at high velocity and must be immediately queryable.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Azure Blob Storage with JSON blobs
Why it's wrong here
Unstructured storage, no native SQL querying.
- ✓
Azure Cosmos DB with Core (SQL) API
Why this is correct
Optimized for semi-structured JSON, native SQL API, and high-throughput writes.
- ✗
Azure Data Lake Storage Gen2 with JSON files and PolyBase
Why it's wrong here
PolyBase is for querying, but high-throughput writes to files may cause contention.
- ✗
Azure SQL Database with JSON columns
Why it's wrong here
Supports JSON but not designed for high-throughput writes from IoT.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This DP-203 practice question is part of Courseiva's free Microsoft 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 DP-203 exam.