Nearest Neighbor Query

PostgreSQL: Nearest Neighbor Query Performance on Billions of Geolocation Records

This article discusses the performance of nearest neighbor queries in PostgreSQL and talks about optimization measures that address performance issues.

Sorting GiST Indexes by Leveraging Nearest-neighbor Enhancement in PostgreSQL 9.1

This article discusses the nearest-neighbor enhancement added in PostgreSQL 9.1 for sorting GiST indexes with sample code and examines the performance using test data.