PostGIS New LinestringZ from Linestring w/Raster Sample

gistfile1.txt

/*
  We have to build a new replacement LinestringZ rather than use
  ST_SetPoint() since UPDATE can only change a single row, and
  the column type in question is LinestringZ, not PointZ.
*/
select st_astext(st_makeline(
	array(select st_makepoint(st_x(point), st_y(point), z) as new_point
	from 
	(select st_pointn(wkb_geometry, point_idx) as point,
		st_value(rast, st_pointn(wkb_geometry, point_idx)) as z
		from vermont.roads, vermont.elevation_test,
		(select ogc_fid, generate_series(1, st_numpoints(wkb_geometry)) as point_idx
			from vermont.roads
			where ogc_fid=92884) as point_idxs
		where roads.ogc_fid = point_idxs.ogc_fid
	) as points
	)
))