Book Image

PostGIS Cookbook - Second Edition

By : Pedro Wightman, Bborie Park, Stephen Vincent Mather, Thomas Kraft, Mayra Zurbarán
Book Image

PostGIS Cookbook - Second Edition

By: Pedro Wightman, Bborie Park, Stephen Vincent Mather, Thomas Kraft, Mayra Zurbarán

Overview of this book

PostGIS is a spatial database that integrates the advanced storage and analysis of vector and raster data, and is remarkably flexible and powerful. PostGIS provides support for geographic objects to the PostgreSQL object-relational database and is currently the most popular open source spatial databases. If you want to explore the complete range of PostGIS techniques and expose related extensions, then this book is for you. This book is a comprehensive guide to PostGIS tools and concepts which are required to manage, manipulate, and analyze spatial data in PostGIS. It covers key spatial data manipulation tasks, explaining not only how each task is performed, but also why. It provides practical guidance allowing you to safely take advantage of the advanced technology in PostGIS in order to simplify your spatial database administration tasks. Furthermore, you will learn to take advantage of basic and advanced vector, raster, and routing approaches along with the concepts of data maintenance, optimization, and performance, and will help you to integrate these into a large ecosystem of desktop and web tools. By the end, you will be armed with all the tools and instructions you need to both manage the spatial database system and make better decisions as your project's requirements evolve.
Table of Contents (18 chapters)
Title Page
Packt Upsell
Contributors
Preface
Index

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 four 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
    • Getting detailed building footprints from LiDAR
  • Creating a fixed number of clusters from a set of points:
    • Using the PostGIS function, ST_ClusterKMeansto create K clusters from a set of points
    • Using a minimum bounding circle to visually represent the clusters with the ST_ MinimumBoundingCircle function
  • Calculating a Voronoi diagram:
    • Using the ST_VoronoiPolygon function in order to calculate...