I want to add a deck to my above ground pool. Is it OK to use concrete deck piers that lay on the ground or should I dig a hole and bury 3 feet of the post?

The deack will be 4' off the ground.

Concrete deck piers are typically permitted where the deck is free-standing and does not attach to any other structure.

Check with your code inspector.

It will not be connected to the house... Also, I found some plans and it shows me having a pier every 3.5'. At that rate, I will have around 40 piers, that's seem like an awful lot.