Segmenting Open Street Map Streets Using PostGIS.
This blog post gives an overview on how to segment streets in OSM data.
A street in OSM data is a linestring. A Linestring represents a sequence of points and line segments connecting them. Segmenting is a process of dividing a segment into multiple segments.
Need for Segmenting
Let us suppose there is a big street represented by a linestring. Let us suppose that we interested in a particular part of the street and not the whole street. In such cases we may have to segment the bigger street into small streets.
A figure explaining the above:
Some PostGIS Functions
Before we start with segmentation, let us first try to understand some basic PostGIS functions which are used in segmentation process.
ST_Split function splits geometries and returns a collection of geometries. The code below illustrates an example