Said hook is almost always there, cheapest way to get light is to take some flex, a lampholder and a choc block. Tie a knot into the cord and hang it over the hook. Then hook up the "fixture" with the choc block. Maybe add a chinese paper shade. In old houses you'll often find the hooks screwed into the plugs of the old gas lines. Solid as a rock because the gas lines are usually tightly secured to a joist. However, some time ago there were quite heavy fixtures. my aunt once offered us a few old ones that were nearly too heavy for me to lift (I guess around 50kg or so), and ugly as hell.
Fixtures that go directly to the ceiling are usually screwed to the lathes or drywall, connections are made inside the fixture (either a choc block or the feeder wires are sleeved with silicone tubing and hooked up to the light socket directly).
The last picture looks pretty much like an ordinary Ikea fixture you'd find in at least half of Vienna's houses.
