Depends on the provider. I've checked the pricing of 4 top relational database cloud vendors (Google, Amazon, Azure, IBM) and they all charge for the number of

Depends on the provider. I've checked the pricing of 4 top relational database cloud vendors (Google, Amazon, Azure, IBM) and they all charge for the number of CPU cores and RAM you buy, not by the number of rows scanned like PlanetScale did in the post you refer to. They'll be more expensive than buying your own server but not nearly what PlanetScale charges for full table scan queries.