ST_IsPolygonCW — Tests if Polygons have exterior rings oriented clockwise and interior rings oriented counter-clockwise.
Returns true if all polygonal components of the input geometry use a clockwise orientation for their exterior ring, and a counter-clockwise direction for all interior rings.
Returns true if the geometry has no polygonal components.
Closed linestrings are not considered polygonal components, so you would still get a true return by passing a single closed linestring no matter its orientation.
If a polygonal geometry does not use reversed orientation for interior rings (i.e., if one or more interior rings are oriented in the same direction as an exterior ring) then both ST_IsPolygonCW and ST_IsPolygonCCW will return false.
This function supports 3d and will not drop the z-index.
This function supports M coordinates.