Describe considerations for working with non-relational data on Azure →mediumMultiple ChoiceObjective-mapped
DP-900 Practice Question: Describe considerations for working with non-relational data on Azure
A startup develops a mobile application that stores user preferences as simple key-value pairs. The app is only used in North America, and the team needs low-latency reads and writes with minimal cost. They do not require global distribution or complex querying. Which Azure data store should they choose?
⚠ Common exam trap
It's easy for candidates to confuse Azure Cosmos DB Table API with Azure Table Storage, assuming the Cosmos DB version is always better, but they fail to consider the cost implications and the fact that Azure Table Storage is sufficient for simple, single-region key-value workloads without global distribution.
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 Table Storage
Azure Table Storage is the correct choice because it provides a cost-effective, low-latency key-value store for simple data like user preferences, with no need for global distribution or complex querying. It offers single-digit millisecond latency for reads and writes within a single region, and its pay-per-request pricing model minimizes cost for a startup. The Table API in Azure Cosmos DB would be overkill and more expensive for this North America-only, non-distributed scenario.
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 Cosmos DB (SQL API)
Why it's wrong here
Azure Cosmos DB SQL API is a document-oriented NoSQL database that automatically indexes every property and supports rich SQL-style queries over JSON documents. This flexible querying engine and its associated Request Unit (RU) consumption drive up cost, especially when you only need a simple key lookup. Without a requirement for document querying, global distribution, or a SQL query language, this offering is much more expensive than Azure Table Storage for the same basic key-value data.
When this WOULD be correct
A global e-commerce platform requires a multi-region, low-latency NoSQL database with SQL querying support and automatic failover for high availability. Azure Cosmos DB (SQL API) would be the correct choice.
- ✗
Azure Cosmos DB (Table API)
Why it's wrong here
Azure Cosmos DB Table API offers the same table row schema as Azure Table Storage but runs on Cosmos DB's globally distributed platform with RU-based throughput provisioning. Even without enabling multi-region writes, the account requires a minimum amount of provisioned throughput per container, making the baseline cost higher than Azure Table Storage alone. For a single-region, non-distributed workload, the added multi-region and SLA capabilities are simply unnecessary overhead.
When this WOULD be correct
A company needs a globally distributed, low-latency key-value store with multi-region writes and automatic failover, and is willing to pay higher costs for those capabilities.
- ✓
Azure Table Storage
Why this is correct
Azure Table Storage is a schema-less NoSQL key-value store that enables fast, cost-effective point lookups via a partition key and row key. It automatically indexes these keys and has no minimum throughput provisioning, so you pay only for the structured storage you actually use. For a single-region, latency-tolerant mobile app with simple key-value data, it delivers the lowest cost with sufficient performance.
- ✗
Azure SQL Database
Why it's wrong here
Azure SQL Database is a fully managed relational database engine with ACID transactions, T-SQL queries, and a rigid schema. Using it to store simple key-value pairs would force you to design tables, define primary keys, and pay for compute (DTUs/vCores) and storage that are far beyond the need for lightweight point lookups. The operational and licensing costs cannot compete with a dedicated NoSQL key-value store for this scenario.
When this WOULD be correct
A question where the application requires complex queries, joins, transactions, or structured relational data with ACID guarantees, and cost is less of a concern, such as a financial system needing strict consistency.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The DP-900 exam frequently reuses these exact scenarios with slightly different constraints.
✓Azure Table StorageCorrect answer▾
Why this is correct
Azure Table Storage is a schema-less NoSQL key-value store that enables fast, cost-effective point lookups via a partition key and row key. It automatically indexes these keys and has no minimum throughput provisioning, so you pay only for the structured storage you actually use. For a single-region, latency-tolerant mobile app with simple key-value data, it delivers the lowest cost with sufficient performance.
✗Azure Cosmos DB (SQL API)Wrong answer — click to see why▾
Why this is wrong here
Azure Cosmos DB (SQL API) is a globally distributed, multi-model database with high cost and complexity, which is overkill for a simple key-value store with North America-only, low-latency, low-cost requirements.
★ When this WOULD be the correct answer
A global e-commerce platform requires a multi-region, low-latency NoSQL database with SQL querying support and automatic failover for high availability. Azure Cosmos DB (SQL API) would be the correct choice.
Why candidates choose this
Candidates may assume that any key-value or NoSQL scenario requires Cosmos DB, overlooking the simpler and cheaper Azure Table Storage for non-global, low-cost needs.
✗Azure Cosmos DB (Table API)Wrong answer — click to see why▾
Why this is wrong here
Azure Cosmos DB (Table API) is overkill and more expensive than Azure Table Storage for a simple key-value store limited to North America without global distribution needs.
★ When this WOULD be the correct answer
A company needs a globally distributed, low-latency key-value store with multi-region writes and automatic failover, and is willing to pay higher costs for those capabilities.
Why candidates choose this
Candidates may confuse the Table API with Azure Table Storage, assuming they are equivalent, or think Cosmos DB's premium features are always better without considering cost.
✗Azure SQL DatabaseWrong answer — click to see why▾
Why this is wrong here
Azure SQL Database is a relational database with higher cost and complexity than needed for simple key-value storage, and it does not provide the low-latency, low-cost key-value access that Azure Table Storage offers.
★ When this WOULD be the correct answer
A question where the application requires complex queries, joins, transactions, or structured relational data with ACID guarantees, and cost is less of a concern, such as a financial system needing strict consistency.
Why candidates choose this
Candidates may associate Azure SQL Database with reliable data storage and think it can handle any data type, overlooking the specific requirement for simple key-value pairs and minimal cost.
Analysis generated from the official DP-900blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
Go deeper
Related to this question
Learn chapter
Data Roles and Core Concepts
Key term
Azure Cosmos DB
Azure Cosmos DB is a fully managed, globally distributed NoSQL database service that offers fast reads and writes anywhere in the world with automatic scaling and multiple consistency models.
Key term
Data
Data is raw, unprocessed information, like numbers, words, or measurements, that can be stored, processed, and analyzed by computers.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This DP-900 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-900 exam.