- A
Azure Data Lake Storage Gen2 for all data.
Why wrong: Data Lake Storage is a great store for historical data but does not provide real-time stream ingestion. You would still need an ingestion service. Additionally, storing every event directly to Data Lake without batching could be inefficient.
- B
Azure Event Hubs with Capture to Azure Data Lake Storage.
Event Hubs can handle millions of events per second. The Capture feature automatically writes ingested events to Data Lake Storage in Avro format (or JSON). For real-time dashboards, you can use Stream Analytics to query the Event Hubs stream. This provides a seamless, low-operational-overhead solution.
- C
Azure Cosmos DB for both real-time and historical data.
Why wrong: Cosmos DB can support real-time queries but at high write throughput it becomes very expensive. Storing billions of raw events in Cosmos DB for long-term is not cost-effective and does not utilize its strengths as a NoSQL document database.
- D
Azure Time Series Insights (TSI) Standard.
Why wrong: TSI is purpose-built for IoT time-series data and can handle high cardinality. However, it is not ideal for storing raw JSON events long-term at massive scale, and the warm/cold store costs may be higher than Data Lake Storage. Also, TSI does not provide the flexibility of using other analytics tools on the data.
AZ-305 Design data storage solutions Practice Question
This AZ-305 practice question tests your understanding of design data storage solutions. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A company ingests millions of IoT events per second from sensors around the world. Each event is a JSON message with timestamp, device ID, and readings. They need to support real-time analytics dashboards and also store all raw data for long-term historical analysis. They want to minimize operational overhead. Which Azure data storage solution should they recommend?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue:
"minimum / minimize"Why it matters: Asks for the least resource use — fewest addresses, smallest subnet, lowest overhead. Eliminate over-provisioned options even if they would technically work.
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 Event Hubs with Capture to Azure Data Lake Storage.
Azure Event Hubs is designed for high-throughput data ingestion, capable of handling millions of events per second. By enabling the Capture feature, data is automatically and durably persisted to Azure Data Lake Storage in Avro format, providing a serverless, low-latency pipeline for real-time dashboards while storing raw data for long-term analytics. This minimizes operational overhead by eliminating the need to manage separate ingestion and storage infrastructure.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
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 Data Lake Storage Gen2 for all data.
Why it's wrong here
Data Lake Storage is a great store for historical data but does not provide real-time stream ingestion. You would still need an ingestion service. Additionally, storing every event directly to Data Lake without batching could be inefficient.
- ✓
Azure Event Hubs with Capture to Azure Data Lake Storage.
Why this is correct
Event Hubs can handle millions of events per second. The Capture feature automatically writes ingested events to Data Lake Storage in Avro format (or JSON). For real-time dashboards, you can use Stream Analytics to query the Event Hubs stream. This provides a seamless, low-operational-overhead solution.
Clue confirmation
The clue word "minimum / minimize" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Azure Cosmos DB for both real-time and historical data.
Why it's wrong here
Cosmos DB can support real-time queries but at high write throughput it becomes very expensive. Storing billions of raw events in Cosmos DB for long-term is not cost-effective and does not utilize its strengths as a NoSQL document database.
- ✗
Azure Time Series Insights (TSI) Standard.
Why it's wrong here
TSI is purpose-built for IoT time-series data and can handle high cardinality. However, it is not ideal for storing raw JSON events long-term at massive scale, and the warm/cold store costs may be higher than Data Lake Storage. Also, TSI does not provide the flexibility of using other analytics tools on the data.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often confuse Azure Data Lake Storage as a complete solution for both ingestion and storage, overlooking the need for a dedicated event ingestion service like Event Hubs to handle high-throughput streaming data before persisting it to the lake.
Detailed technical explanation
How to think about this question
Event Hubs Capture uses a time or size window (e.g., every 5 minutes or 200 MB) to batch incoming events into Avro files stored in Azure Data Lake Storage, ensuring exactly-once semantics for the captured data. Under the hood, Event Hubs partitions data across multiple consumers, allowing real-time analytics via Stream Analytics or Apache Spark while the Capture process runs asynchronously in the background. In a real-world scenario, this pattern is commonly used for IoT telemetry pipelines where dashboards require sub-second latency and historical queries run on petabyte-scale data lakes.
KKey Concepts to Remember
- Read the scenario before looking for a memorised answer.
- Find the constraint that changes the correct option.
- Eliminate answers that are true in general but not in this case.
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A media company stores terabytes of video archives that are accessed once a year for audit purposes. Moving these objects to a cold storage tier (Azure Archive, S3 Glacier, or Google Nearline) costs a fraction of hot storage. Questions like this test whether you understand storage tiers, access frequency tradeoffs, and retrieval latency requirements.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
- →
Design data storage solutions — study guide chapter
Learn the concepts, then practise the questions
- →
Design data storage solutions practice questions
Targeted practice on this topic area only
- →
All AZ-305 questions
999 questions across all exam domains
- →
Microsoft Azure Solutions Architect Expert AZ-305 study guide
Full concept coverage aligned to exam objectives
- →
AZ-305 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related AZ-305 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Design identity, governance, and monitoring solutions practice questions
Practise AZ-305 questions linked to Design identity, governance, and monitoring solutions.
Design data storage solutions practice questions
Practise AZ-305 questions linked to Design data storage solutions.
Design business continuity solutions practice questions
Practise AZ-305 questions linked to Design business continuity solutions.
Design infrastructure solutions practice questions
Practise AZ-305 questions linked to Design infrastructure solutions.
SAA-C03 VPC practice questions
Practise AZ-305 questions linked to SAA-C03 VPC.
SAA-C03 S3 lifecycle policy questions
Practise AZ-305 questions linked to SAA-C03 S3 lifecycle policy questions.
SAA-C03 RDS Multi-AZ questions
Practise AZ-305 questions linked to SAA-C03 RDS Multi-AZ questions.
SAA-C03 IAM policy practice questions
Practise AZ-305 questions linked to SAA-C03 IAM policy.
SAA-C03 Route 53 failover questions
Practise AZ-305 questions linked to SAA-C03 Route 53 failover questions.
SAA-C03 CloudFront practice questions
Practise AZ-305 questions linked to SAA-C03 CloudFront.
SAA-C03 NAT gateway questions
Practise AZ-305 questions linked to SAA-C03 NAT gateway questions.
SAA-C03 VPC endpoint questions
Practise AZ-305 questions linked to SAA-C03 VPC endpoint questions.
Practice this exam
Start a free AZ-305 practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this AZ-305 question test?
Design data storage solutions — This question tests Design data storage solutions — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Azure Event Hubs with Capture to Azure Data Lake Storage. — Azure Event Hubs is designed for high-throughput data ingestion, capable of handling millions of events per second. By enabling the Capture feature, data is automatically and durably persisted to Azure Data Lake Storage in Avro format, providing a serverless, low-latency pipeline for real-time dashboards while storing raw data for long-term analytics. This minimizes operational overhead by eliminating the need to manage separate ingestion and storage infrastructure.
What should I do if I get this AZ-305 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "minimum / minimize". Asks for the least resource use — fewest addresses, smallest subnet, lowest overhead. Eliminate over-provisioned options even if they would technically work.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Last reviewed: Jun 11, 2026
This AZ-305 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 AZ-305 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.