We have a set of thousands of points and want to group all of those which are within 100m distance from each other (to get the centroid from each group). A first idea was to build 100m buffers around each point and to union/group all intersecting/overlapping polygons to one (but there can also be non-overlapping polygons within one cluster, see screenshot) - after that, we could simply calculate the centroid from the merged polygons. But I do not know how to do that in Postgis (in QGIS there is a simple tool called 'dissolve' that merges overlapping polygons, but we want to automatize the process)
