#vector-search

2 posts

September 15, 2026 · 9 min read

Search in Polecat, Part 2: Vector search on a computed VECTOR column

SQL Server 2025 added a VECTOR type. Polecat 5.28 reaches it with a persisted computed column over the JSON document body, which means no write path changes and no backfill. Exact k-nearest-neighbour, three metrics that are all distances, and the one real limit.

polecat sql-server dotnet critter-stack

September 15, 2026 · 6 min read

Search in Polecat, Part 3: Hybrid search and reciprocal rank fusion

Keyword search and vector search fail in different places, so a document both rank well beats either one's favourite. How Polecat 5.29 fuses the two rankings with RRF, why only the ranks are fused and never the scores, and why candidate depth has to exceed the limit.

polecat sql-server dotnet critter-stack