Looking for a database that uses SQL/ postgres extensions as its interface and has a usage based model like DynamoDB. I quite like DynamoDB since it frees me up from thinking about instance types, memory requirements or whatever.
DynamoDB has the concept of CUs ( compute units ) which are of two types - RCU.(read compute unit) and WCU (write compute unit). You pay for the CUs that are used + charges for storage. Each operation consumes certain number of CUs. You pay for the CUs used. So something like that but for SQL and hopefully compatible with the standard.
https://aws.amazon.com/rds/aurora/serverless/