PostGIS Cookbook - Second Edition

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Now we are nearly ready for routing. The centerline calculation we have is a good approximation of a straight skeleton, but is still subject to the noisiness of the natural world. We'd like to eliminate that noisiness by choosing our features and emphasizing them through routing. First, we need to prepare the table to allow for routing calculations, as shown in the following commands:

ALTER TABLE chp06.voronoi_intersect ADD COLUMN gid serial;
ALTER TABLE chp06.voronoi_intersect ADD PRIMARY KEY (gid);
    
ALTER TABLE chp06.voronoi_intersect ADD COLUMN source integer;
ALTER TABLE chp06.voronoi_intersect ADD COLUMN target integer;

Then, to create a routable network from our skeleton, enter the following commands:

SELECT pgr_createTopology('voronoi_intersect', ...