Which feature in Azure SQL Database is responsible for automatic performance tuning?

Automatic Tuning is a feature in Azure SQL Database that is designed to enhance database performance without requiring manual intervention. It employs algorithms to continuously monitor the workload of the database, identifies performance bottlenecks, and applies various tuning recommendations to optimize query performance.

The feature includes several automatic actions such as automatic index management, which helps in adding and dropping indexes based on the performance of queries. This smart management ensures that the database operates efficiently with optimal performance by adapting to changing workloads dynamically. Additionally, Automatic Tuning can also automatically adjust query plans based on usage patterns, further aiding in enhancing overall database performance.

Other options like Auto-Scaling, Performance Insights, and SQL Optimization address different aspects of database management but do not specifically refer to the automated process for performance tuning as offered by Automatic Tuning. Auto-Scaling is related to adjusting resource allocation based on demand, Performance Insights involves monitoring and reporting on performance metrics, and SQL Optimization typically entails strategies or methods applied by the database administrator to enhance query performance rather than automatic adjustments made by the system itself.