Simplifying geometries

There will be many times when you will need to generate a less detailed and lighter version of a vector dataset, as you may not need too-detailed features for several reasons. Think about a case where you are going to publish the dataset to a website and performance is a concern, or maybe you need to deploy the dataset to a colleague who does not need too much detail because he or she is using it for a large-area map. In all of these cases, GIS tools provide you the implementation of simplification algorithms that reduce unwanted details from a given dataset. Basically, these algorithms reduce the vertex numbers comprised in a certain tolerance, which is expressed in units measuring distance.

For this purpose, PostGIS provides you the ST_Simplify and ST_SimplifyPreserveTopology functions. In many cases, they are the right solutions for simplification tasks, but in some cases, especially for polygonal features, they are not the best option out there and you will need...