union Or Null
Calculates the union of a collection of geometries. The union combines those parts of the input geometries which overlap into a single geometry.
If the collection contains geometries of differing dimensionality, the geometry with the higher dimensionality is returned. For example, a polygon is returned if the given a collection contains polygons, polylines, and points.
Supports true curves.
Return
The union of all the geometries in the given collection.
Since
200.1.0