AZ-900 Describe Azure architecture and services Practice Question
Which Azure service provides a managed, serverless SQL database that scales automatically and pauses when not in use?
⚠ Common exam trap
It's easy for candidates to confuse 'serverless' with 'Cosmos DB' because Cosmos DB also offers a serverless mode, but they overlook that the question specifically asks for a SQL database, not a NoSQL database.
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 SQL Database Serverless
Azure SQL Database Serverless is the correct answer because it is a compute tier for single databases that automatically scales compute resources based on workload demand and pauses the database during periods of inactivity, charging only for storage when paused. This aligns directly with the question's requirement for a managed, serverless SQL database that scales automatically and pauses when not in use.
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 SQL Database General Purpose tier
Why it's wrong here
Azure SQL Database General Purpose tier runs on provisioned compute that is always reserved, never auto-pausing, so you pay per hour even when the database is idle. This tier is optimized for predictable, steady-state workloads that need consistent performance, not for intermittent usage where auto-pause would save cost. Unlike Serverless, it does not scale down to zero compute or suspend billing during inactivity, making it unsuitable for the requirement to pause without manual intervention.
- ✓
Azure SQL Database Serverless
Why this is correct
Azure SQL Database Serverless is the correct option because it automatically scales compute based on load and auto-pauses after a period of inactivity, at which point compute billing stops and only storage-related costs remain. It bills per second for the actual compute used, providing cost savings for irregular or bursty workloads. This is exactly the functionality the question describes, distinguishing it from provisioned tiers that run continuously.
- ✗
Azure Cosmos DB Serverless
Why it's wrong here
Azure Cosmos DB Serverless is a consumption-based mode for Azure Cosmos DB, which is a multi-model NoSQL database service, not a relational SQL database. While it also scales and pauses based on traffic, it is a completely different service and would require using Cosmos DB instead of Azure SQL. The question asks about Azure SQL options, so this cannot satisfy the requirement of a serverless mode for Azure SQL Database.
- ✗
Azure SQL Managed Instance
Why it's wrong here
Azure SQL Managed Instance is a fully managed SQL Server instance that runs continuously on dedicated infrastructure with fixed compute resources. It is designed for lift-and-shift migrations of on-premises SQL Server workloads and offers features like virtual network integration, but it lacks a serverless or auto-pause capability. Because it is always running, it incurs constant charges and does not meet the requirement for pausing when inactive, making it incorrect here.
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 |
Go deeper
Related to this question
Learn chapter
Azure Regions and Geographies
Key term
Serverless
Serverless is a cloud computing model where the cloud provider manages the servers, and you only pay for the actual compute time your code uses, without having to worry about provisioning or maintaining infrastructure.
Key term
Azure SQL Database
Azure SQL Database is a fully managed relational database-as-a-service (DBaaS) in Microsoft Azure, based on the SQL Server engine, that handles scaling, backups, patching, and high availability automatically.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This AZ-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 AZ-900 exam.