Preface

PostGIS (pronounced post-jis) is a spatial database extender for the PostgreSQL open source relational database management system. It’s the most powerful open source spatial database engine. It adds to PostgreSQL several spatial data types and over 300 functions for working with these spatial types. It does for PostgreSQL what Oracle Spatial/Locator does for Oracle, what IBM DB2/Information spatial DataBlades do for DB2 and Informix, and what geometry/geography types packaged in Microsoft SQL Server 2008+ do for SQL Server. PostGIS supports many of the OGC/ISO SQL/MM-compliant spatial functions you’ll find in these other OGC-compliant databases as well as numerous additional ones that are unique to PostGIS.

Readers coming from other ANSI/ISO-compliant spatial databases or other relational databases such as those we’ve mentioned, will feel right at home with Postgre-SQL/PostGIS. PostgreSQL is the most ANSI/ISO SQL-compliant database management system around, and it supports most of the ANSI-SQL92/2003 standards and some of the 2006/2008 standards. In a similar vein, PostGIS supports many of the industry-standard OGC/ISO SQL/MM spatial database functions, types, and operations.

The main raison d’être of this book is to provide a companion volume to the official PostGIS documentation—to serve as a guide book for navigating through the hundreds of functions offered by PostGIS. We wanted to create a book that will catalog many of the common spatial problems we’ve come across and various strategies for solving them with PostGIS.

Above and beyond our primary mission, we hope to lay the foundation for thinking spatially. We hope that readers will be able to adapt our numerous examples and recipes to their own field of endeavor, and perhaps even to spawn creative scions of their own.