Neither. The right answer is to use the GIS Spatial Type for a point. All of those database have their own implementation.
PostgreSQL's PostGIS is easily the most full featured GIS implementation,
CREATE TABLE foo(
gid int GENERATED BY DEFAULT AS IDENTITY,
geog geography(POINT)
);
I would highly suggest going PostgreSQL, and checking out the book PostGIS in Action i fyou're new to this. See also,