Database Reference
In-Depth Information
postgis_cookbook -user me -host localhost
prefixtables cleveland_ -clean
Ourdatasetmaybequitelargeandtakesometimetoprocessandimport.Bepatient
and the end of the output should say something like the following:
Create Topology success
#########################
size of streets: 90013
size of splitted ways : 224534
finished
Our new vector table, by default, is named
cleveland_ways
. If no
-pre-
fixtables
flag were used, the table name would just be
ways
.
How it works...
osm2pgrouting
is a powerful tool. In this case, it creates eight tables from our
input file. Of those eight, we'll address the two primary tables: the
ways
table and
the
nodes
table.
Our
ways
tableisatableofthelinesrepresentingallofourstreets,roads,trails,and
soonthatareinOSM.The
nodes
tablecontainsalloftheintersections.Thishelps
us identify the beginning and end points for routing.
Let's apply an A* (A star) routing approach to this problem.
Tip
A* is an extension of Dijkstra's algorithm, which uses a heuristic to speed up
the search for the shortest path, at the cost of occasionally not finding the op-
timum route. See
http://en.wikipedia.org/wiki/A*
and
http://en.wikipedia.org/wiki/
File:Astar_progress_animation.gif
for more information.
