Databases

Abstract

As geographic information storage and applications matured, their use as databases followed. A typical geoconfiguration consists of a map combined with an object-relational database, similar to the 300 year-old example shown in Fig. 3.1. Other geographic databases, such as the well-known Earth browsers Bing or Google Maps, contain a simple, but large, collection of raster orthophoto maps. Vector maps require a far more sophisticated data model and are usually rendered while being read from the database and presented on a display device. Sections 3.1–3.5 provide basic knowledge about database theory. The two most common models, namely the relational and the object-oriented model, are explained. The second part of this chapter (Sects. 3.6–3.12) explains the geospecific aspects of database technology. It starts with Sect. 3.6 about spatial databases with vector and raster models, referencing the relevant standards. Section 3.7 covers spatial queries and filtering. Section 3.8 explains indexing, which supports acceleration of queries. Section 3.9 provides an overview of network databases and some prominent network search algorithms. Section 3.10 is dedicated to raster databases, and Sect. 3.11 introduces time in the context of spatiotemporal databases. Section 3.12 summarizes the most widespread database software solutions.