PostGIS Cookbook - Second Edition

How to do it...

Now that the data is loaded, we can run a quick test. We'll use a simple algorithm called Dijkstra to calculate the shortest path from node 5 to node 12.

Dijkstra's algorithm is an effective and simple routing algorithm that runs a search on all available paths from point A to point B in a network, also known as the graph structure. It is not the most efficient routing algorithm, but will always find the best route. For more information on Dijkstra's algorithm, refer to Wikipedia, which has a good explanation, with illustrations, at http://en.wikipedia.org/wiki/Dijkstra%27s_algorithm. The animation at http://en.wikipedia.org/wiki/File:Dijkstras_progress_animation.gif is particularly helpful.

An important point to note is that ...