[postgis-users] Geoprocessing & BigData

[Pierre Racine]

> @Vincent : For ArcGIS Union, please see here.
> http://resources.esri.com/help/9.3/arcgisengine/java/gp_toolref/analysis_
> tools/union_analysis_.htm

ArcGIS Union resume to removing overlaps from the union of two tables. Look at the ST_DifferenceAgg() example in the PostGIS Addons:

https://github.com/pedrogit/postgisaddons/blob/master/postgis_addons.sql

This  produce a clean table (layer) without overlaps from the union of two (polygon) tables (layers).

Pierre