PostGIS Cookbook - Second Edition

How to do it...

The steps you need to do to complete this recipe are as follows:

1. Set the PostgreSQL search_path variable such that all your newly created database objects will be stored in the chp03 schema, using the following code:

      postgis_cookbook=# SET search_path TO chp03,public; 

 

 

2. Suppose you need a less-detailed version of the states layer for your mapping website or to deploy to a client; you could consider using the ST_SimplifyPreserveTopology function as follows:

      postgis_cookbook=# CREATE TABLE states_simplify_topology AS 
        SELECT ST_SimplifyPreserveTopology(ST_Transform(          the_geom, 2163), 500) FROM states;

3. The previous command works quickly, using a variant of the Douglas-Peucker algorithm, and effectively reduces the vertex ...