There's as many dimensions to that question as there are services in a w s, which is to say, like a higher than afnull infinity exactly. And the way that i would generally suggest people decide whether or not it's a good idea to adopt particular service has to do with the way that their operational footprint works in terms of overhead. Almost always you should just use r d s, because the operational footprint of that is, amazon configures and manages the tremendous complexity of operating a relational data store in production.