Comment by fc417fc802

The point about the sandwich was that the inputs to a function are not correctly referred to as its output. Those are distinct things.

If you wanted to further extend the analogy to apply to schemas then I guess the recipe would be the database engine and the final product that you eat would be the file layout. Knowing that the final dish will include jam does not mean that you have the final dish in your possession. The jam sitting on the counter is not the final dish.

Importantly, you don't even know how I'm going to use the jam. I could put it only on one half, or I could arrange it in stripes, or I could even use more than two pieces of bread! I might not even make a sandwich! I could even throw it all in a blender and make a (disgusting) smoothie.