postgis - How to add vertices to existing linestrings?

If I have

Linestring(1 2, 1 5, 1 9)

and a

Point(1 3)

Is there any function that can merge linestring and point preserving the order so output would be:

Linestring(1 2, 1 3, 1 5, 1 9)

Answer

If the LineString is simply to be subdivided at a position closest to the given Point, you could do what you want with this (splits LineString at closest Point to given Point and remerges the two segements afterwards)

SELECT ST_AsText(
         ST_LineMerge(
           ST_Union(
             ST_Line_Substring(line, 0, ST_Line_Locate_Point(line, point)),
             ST_Line_Substring(line, ST_Line_Locate_Point(line, point), 1)
       )))
FROM  ST_GeomFromText('Linestring(1 2, 1 5, 1 9)') as line, 
      ST_GeomFromText('Point(1 3)') as point;

However, if your Point is not supposed to be projected on the LineString, this will not work.