Which platform supports automatic index management?

Automatic index management is a feature that allows a database system to automatically create, drop, or rebuild indexes based on workload patterns and performance metrics. This feature is designed to optimize query performance without requiring manual intervention from database administrators.

SQL Database, which is a part of the Azure platform, supports automatic tuning features, including automatic indexing. This includes automatic index creation when the system identifies that a new index can improve the performance of queries, as well as automatic dropping of indexes that are no longer being used, therefore preventing unnecessary resource consumption. Through this automated process, SQL Database helps maintain optimal performance as workloads change over time.

In contrast, while SQL Server on-premises also has features related to index management, it does not have the fully automated capabilities that Azure SQL Database provides. Azure Blob Storage is primarily focused on object storage and does not deal with indexing, and Azure Cosmos DB, although it manages indexes automatically in some capacity, does not include the full suite of automatic index management features found in SQL Database. Thus, Azure SQL Database is the preferred answer for this question regarding automatic index management capabilities.