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 and Oracle Locator do for Oracle, what IBM DB2 Spatial Extender and IBM Informix Spatial DataBlade do for DB2 and Informix, and what the geometry and 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 PostgreSQL and PostGIS. PostgreSQL is the most ANSI/ISO SQL–compliant database management system around. In a similar vein, PostGIS supports many of the industry-standard OGC/ISO SQL/MM spatial database functions, types, and operations.