Actually, I think this is what Vertica is for (VoltDB was a Vertica spin-off). Volt is intended for OLTP workloads whereas Vertica is designed for OLAP, especially giant star-schema workloads like the post described.

Vertica is legit, we tested it against a billion rows on a single server and it didn't blink and eye. It reads compressed data, and optimizes compression based on the column's data type for that ec2 price you could get a few years of vertica licenses

Vertica has EC2 instances available, i am trying to figure out pricing. They are a distributed DB, but not all in RAM.

Vertica was C-Store, a column oriented store for analysis. VoltDB was H-Store, an in-memory database for very fast OLTP. (From testing VoltDB, it screams, and scales nearly linearly.)

I'm not sure HStore/VoltDB was a "spin off" of Vertica - they are quite different models fundamentally.

They use different architectures but there is a real organizational connection between the two products. I interviewed with the VoltDB team at Vertica's office.