Introduction

Beyond being a spatial database with the capacity to store and query spatial data, PostGIS is a very powerful analytical tool. What this means to the user is a tremendous capacity to expose and encapsulate deep spatial analyses right within a PostgreSQL database.

The recipes in this chapter can roughly be divided into three main sections:

• Highly optimized queries::

  • Improving proximity filtering with KNN

  • Improving proximity filtering with KNN – advanced

• Using the database to create and modify geometries:

  • Rotating geometries

  • Improving ST_Polygonize

  • Translating, scaling, and rotating geometries – advanced

  • Generating detailed building footprints from LiDAR

• Using external libraries to aid advanced analyses:

  • Using external scripts to embed new functionality in order to calculate a Voronoi diagram

  • Using external scripts to embed other libraries in order to calculate a Voronoi diagram – advanced