The first "n" points near a polygon? (spatialite or postgis query)

I've two spatial dataset, the fist one is a polygons layers (My_polygons) and the second one is a points layer (My_points).

I need to find, for each polygons, the "nearest" "N" points (N=10) using a spatial query in spatialite or postgis and store this information somewhere in my database for future queries.