Not to jump da gun, but those supports are what would be used to keep posts from rotting in the ground. Pressure treated lumber will last in the ground longer than untreated, but still if above ground, it will last longer. Obviously if you are on a hillside, and stability is of concern, it is better to dig holes and sink posts into ground. On level ground it is less of a concern.
Called post support pier and cost about $6 at home center stores.
Called post support pier and cost about $6 at home center stores.