Hybrid GIS and Linux geeks know that the open-source PostGIS gives support for geographic objects to PostgreSQL, allowing the relational database to serve as the back end for ArcGIS, GRASS GIS and other geospatial programs. The new 2nd edition of PostGIS in Action from Regina O. Obe and Leo S. Hsu teaches readers of all levels to write spatial queries that solve real-world problems. Obe and Hsu start by getting readers' feet wet with a background in vector-, raster- and topology-based GIS, followed by a tutorial in analyzing, viewing and mapping data. Readers learn 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. The book covers PostGIS 2.0 and 2.1, PostgreSQL 9.1, 9.2 and 9.3 features and shows how to integrate PostGIS with other GIS tools.