13.1. Introducing PostGIS

PostGIS is a spatial (or geographic) extension of the popular open source PostgreSQL relational database. This chapter focuses on using the normal tabular components of PostgreSQL in conjunction with the spatial data management functions of PostGIS.

For more in-depth help with PostgreSQL, I recommend O'Reilly's Practical PostgreSQL (http://www.oreilly.com/catalog/ppostgresql/) and the PostgreSQL web site http://www.postgresql.org.

PostGIS is an open source extension developed by Refractions Research. Their web site (http://postgis.refractions.net) gives this summary of the product:

PostGIS adds support for geographic objects to the PostgreSQL object-relational database. In effect, PostGIS "spatially enables" the PostgreSQL server, allowing it to be used as a backend spatial database for geographic information systems (GIS), much like ESRI's SDE or Oracle's Spatial extension.