In a previous recipe, we used the
ST_SimplifyPreserveTopology function to try to generate a simplification of a polygonal PostGIS layer.
Unfortunately, while that function works well for linear layers, it produces topological anomalies (overlapping and holes) in shared polygon borders. You used an external toolset (
GRASS) to generate a valid topological simplification.
In this recipe, you will use the PostGIS topology support to perform the same task within the spatial database without needing to export the dataset to a different toolset.
To get started, follow the ensuing steps: