Name
ST_GeneratePoints — Generates random points contained in a Polygon or MultiPolygon.
Synopsis
geometry ST_GeneratePoints(
                g
                geometry
            , 
                npoints
                integer
            );
geometry ST_GeneratePoints( geometry g ,  integer npoints ,  integer seed = 0 );
Description
            ST_GeneratePoints generates a given number of pseudo-random points
            which lie within the input area.
            The optional seed is used to regenerate a deterministic sequence of points,
            and must be greater than zero.
        
Availability: 2.3.0
Enhanced: 3.0.0, added seed parameter
Examples
                        
SELECT ST_GeneratePoints(geom, 12, 1996)
FROM (
    SELECT ST_Buffer(
        ST_GeomFromText(
        'LINESTRING(50 50,150 150,150 50)'),
        10, 'endcap=round join=round') AS geom
) AS s;