So far, we have learned how to store geospatial data in a PostGIS database. In fact, any database management system can do that; spatial information can be encoded and stored in an ordinary DBMS-friendly format, be it blob, byte array, or text-based exchange format. What makes the spatial database special (and the PostGIS extension worth installing) is the rich toolset designed for analyzing, transforming, validating, querying, and extracting metrics from spatial information. In this chapter, we will learn how to harness the power of PostGIS spatial functions to gain meaningful insights from geodata. We will focus on the following topics:
- Composing and decomposing geometries
- Spatial measurement
- Geometry bounding boxes ...
