ST_RemoveRepeatedPoints — Returns a version of the given geometry with duplicated points removed.
geometry ST_RemoveRepeatedPoints(geometry geom, float8 tolerance
Returns a version of the given geometry with duplicated points removed. Will actually do something only with (multi)lines, (multi)polygons and multipoints but you can safely call it with any kind of geometry. Since simplification occurs on a object-by-object basis you can also feed a GeometryCollection to this function.
If the tolerance parameter is provided, vertices within the tolerance of one another will be considered the "same" for the purposes of removal.
This function supports Polyhedral surfaces.
This function supports 3d and will not drop the z-index.