ST_LineFromEncodedPolyline — Creates a LineString from an Encoded Polyline.
geometry ST_LineFromEncodedPolyline(text polyline, integer precision=5);
Creates a LineString from an Encoded Polyline string.
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.
See http://developers.google.com/maps/documentation/utilities/polylinealgorithm
Availability: 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)