CREATE TABLE sample_shapes(skey INTEGER, shape ST_Geometry); INSERT sample_shapes(9901, 'Linestring(0 0 0, 0 5 5, 5 5 5, 5 0 5, 0 0 0)'); INSERT sample_shapes(9902, 'Linestring(0 0 0, 1 1 1, 2 2 2, 3 3 3, 4 4 4)'); SELECT Shape.ST_3DLength() FROM sample_shapes;