ST_LineFromEncodedPolyline — Cria uma LineString de uma Encoded Polyline.
geometry ST_LineFromEncodedPolyline(text polyline, integer precision=5);
Cria uma LineString de uma string Encoded Polyline.
Optional precision specifies how many decimal places will be preserved in Encoded Polyline. Value should be the same on encoding and decoding, or coordinates will be incorrect.
Veja http://developers.google.com/maps/documentation/utilities/polylinealgorithm
Disponibilidade: 2.2.0
-- Create a line string from a polyline
SELECT ST_AsEWKT(ST_LineFromEncodedPolyline('_p~iF~ps|U_ulLnnqC_mqNvxq`@'));
-- result --
SRID=4326;LINESTRING(-120.2 38.5,-120.95 40.7,-126.453 43.252)
-- Select different precision that was used for polyline encoding
SELECT ST_AsEWKT(ST_LineFromEncodedPolyline('_p~iF~ps|U_ulLnnqC_mqNvxq`@',6));
-- result --
SRID=4326;LINESTRING(-12.02 3.85,-12.095 4.07,-12.6453 4.3252)