ST_ForcePolygonCW — Orients all exterior rings clockwise and all interior rings counter-clockwise.
 geometry ST_ForcePolygonCW ( geometry geom );
Forces (Multi)Polygons to use a clockwise orientation for their exterior ring, and a counter-clockwise orientation for their interior rings. Non-polygonal geometries are returned unchanged.
Disponibilità: 2.4.0
            
 Questa funzione supporta il 3d e non distrugge gli z-index. 
            
 Questa funzione supporta le coordinate M.