[eis]

> Dynamo started as a document store

No it didn't. The original Dynamo paper doesn't even include the word "document" once! The title of the paper makes it obvious what kind of system it is: "Dynamo: Amazon’s Highly Available Key-value Store"

You should really do some fact checking on your statements.

Bigtable alone does not make an analytics system. You'll need a lot more around that.

I don't have a trivial use case. We use the jsonb data type in Postgres and have no upfront defined schema for metrics.

Postgres' jsonb can out-perform many of the open source NoSQL databases out there. Our system consists of a single digit of nodes that can handle hundreds of thousands of writes per second and as I mentioned already, billions of rows. A single CPU core can scan though more than a million rows per second. Is it the fastest that there is? No. Is it good enough for most people? Absolutely.