SQL Server Vector Search

Overview

SQL Server 2022 and Azure SQL introduce native vector search capabilities, allowing vector similarity search within traditional relational databases.

Features

Vector Storage:

• VARBINARY columns for vectors
• JSON support for metadata
• Standard SQL operations

Search Capabilities:

• VECTOR_DISTANCE function
• Cosine similarity
• Euclidean distance
• Approximate nearest neighbor

Hybrid Search:

• Combine vector and SQL queries
• Filter by metadata before similarity search
• Join vectors with relational data

Use Cases

• Existing SQL Server applications adding AI
• Hybrid search (SQL + vector)
• Unified data platform
• Enterprise applications with SQL skills

Benefits

• No separate vector database needed
• Leverage existing SQL infrastructure
• ACID transactions for vectors
• Familiar SQL interface
• Enterprise security and compliance

RRF Re-Ranking

Reciprocal Rank Fusion for combining:

• Full-text search results
• Vector similarity results
• SQL query results

Availability

SQL Server 2022, Azure SQL Database