DESCRIPTION    PostGIS is an open source spatial database extender for PostgreSQL. It equals or surpasses proprietary alternatives, allowing the creations of location-aware queries with just a few lines of SQL code, and provides a back-end for mapping, raster analysis, and routing applications with minimal effort.     PostGIS in Action, Second Edition teaches readers of all levels to write spatial queries that solve real-world problems. After covering the background in vector, raster and topology based GIS, it quickly moves into analyzing, viewing, and mapping data. The book shows how to optimize queries for maximum speed, simplify geometries for greater efficiency, analyze rasters, vectorize rasters, better manage data utilizing topologies, and create custom functions for applications. It covers PostGIS 2.0 and 2.1 series, PostgreSQL 9.1- 9.3 features and shows how to integrate with other GIS tools.       　   RETAIL SELLING POINTS    Comprehensive coverage of PostGIS   Applies PostGIS to real-world problems     Significant updates to the first edition         AUDIENCE Familiarity with relational database concepts is helpful but not required. This book is for programmers, GIS and DB practitioners, scientists, researchers, educators, and engineers.   ABOUT THE TECHNOLOGY   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 also adds to PostgreSQL several spatial data types and over 300 functions for working with these spatial types.