I have a geography type linestring *route_geography geography(LineString,4326)*, its a route from point A to point B. Now I have a point C near that line. I want to find the nearest point on that line, lets call it D. And then calculate the distance between D and B.
Should I use *ST_Line_Locate_Point()* to find the point D?
And if I do find the point D should I then use *ST_Line_Substring()* to split up the AB linestring to make a new DB linestring?
These two functions are for geometry type not geography that my data is in, so what should I do?