Which Azure service provides a managed, serverless SQL database that scales automatically and pauses when not in use?
SQL Database Serverless automatically scales and pauses when inactive, billing per second for compute used.
Why this answer
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.
Exam trap
The trap here is that candidates often 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.
How to eliminate wrong answers
Option A is wrong because Azure SQL Database General Purpose tier is a provisioned compute tier that requires manual scaling and does not automatically pause when idle, incurring continuous compute costs. Option C is wrong because Azure Cosmos DB Serverless is a NoSQL database service, not a SQL database, and while it scales automatically, it does not pause when not in use—it charges per request. Option D is wrong because Azure SQL Managed Instance is a fully managed SQL Server instance with fixed compute resources, not serverless, and it does not automatically pause or scale based on demand.