I would guess two issues: 1. In many cases, there is a ~30ms floor on operations if a server is non-local. That's true of virtually all services on AWS -- whet

I would guess two issues: 1. In many cases, there is a ~30ms floor on operations if a server is non-local. That's true of virtually all services on AWS -- whether SQS, SNS, SES, RDS (MySQL/PostgreSQL), etc. 2. In many cases, rows are missing. A table has a million rows. Ten are deleted. It's not compacted. So it's not a simple size lookup. A lot of this depends on how the data is stored/indexed. That's something which is naively pretty slow, but easily optimized.