This is a very interesting abstraction (and service). I can’t help but feature creep and ask for something like Athena, which runs PrestoDB (map reduce) over

This is a very interesting abstraction (and service). I can’t help but feature creep and ask for something like Athena, which runs PrestoDB (map reduce) over S3 files. It could be superior in theory because anyone using that pattern must shoehorn their data stream (almost everything is really a stream) into an S3 file system. Fragmentation and file packing become requirements that degrade transactional qualities.