We are happy to share that DiskANN vector indexing is now in public preview across Azure SQL Database, Azure SQL Managed Instance, and SQL database in Microsoft Fabric. DiskANN is a cutting-edge algorithm for efficient vector similarity search, making it ideal for powering recommendation systems, image and multimedia search, and advanced retrieval-augmented generation (RAG) solutions.

create vector index vec_idx on [dbo].[wikipedia_articles_embeddings]([title_vector]) 
with (metric = 'cosine', type = 'diskann'); 

Built for large-scale vector search, DiskANN integrates seamlessly with the Microsoft SQL query engine, enabling you to combine semantic search with the full power of T‑SQL, joins, filters, analytics, without moving data or adding a separate vector store. This is multimodal, AI-ready search inside the database engine.

This release builds on the general availability of vector data type and vector functions announced earlier this summer, marking the next step toward embedding foundational AI capabilities directly in the database.

Modern AI applications depend on fast approximate nearest neighbor (ANN) search over embeddings. Until now, teams often had to stitch together separate vector databases and ETL pipelines, adding complexity and cost. With DiskANN in Azure SQL and Fabric SQL:

• Keep data where it lives: benefit from SQL’s security, governance, and performance while adding high-performance vector search.
• Compose rich queries: blend vector similarity with business filters and joins for multimodal experiences.
• Scale confidently: DiskANN was designed for very large vector collections, balancing accuracy, query speed, and resource consumption.

For more details on vectors and vectors index, take a look also at this blog post: SQL Server 2025 Embraces Vectors: setting the foundation for empowering your data with AI

Public Preview Notes

We’ve received significant demand for vector indexing support, so we’re releasing this feature early to unblock scenarios that can benefit from it. While the feature is available now, please note that there are some current limitations that may affect adoption in certain use cases. These limitations will be removed in the coming months: stay tuned for updates here.

We’ll update this post as soon as these limitations are removed, in the meantime you can start to use vectors and vector index to simplify your AI solution, together with all the other enterprise-ready features in Azure SQL and SQL database in Fabric!