Of course, you're right, but we didn't know that at the time. It turns out there's nothing we were doing that really warranted using a data warehouse (for that is what InfiniDB was really suited for). We were collecting a lot of numerical, time-series data, bulk loading it and then performing summarised queries periodically.
Mongo, Cassandra, etc are not good fits for this. Vertica was very expensive. In the end we went with a sharded and partitioned MySQL setup (partitioning really is great if you use it well). It's worked very well.
This actually sounds like a great fit for Cassandra and Hadoop. You could use Cassandra's built in TimeUUID as the primary key and have your data pre-sorted on disk in time-series. This would make big queries, using something like Hadoop, very efficient.
Yeah, that's exactly what I suggested in the other comment. If you can get away with sharding, it's the easiest solution, and the developers/DBAs are relatively easy to find.
FYI, for people using less than 1 TB of data, Vertica does have a free community edition. I used Vertica at my last job and it was blazingly fast compared to Hive (like 5x to 10x faster).
For future reference, it really sounds like InfluxDB might be a perfect fit for you. I've been trying to find a reason to use it myself, but we don't do a lot of time-series stuff at work (right now at least).
Mongo, Cassandra, etc are not good fits for this. Vertica was very expensive. In the end we went with a sharded and partitioned MySQL setup (partitioning really is great if you use it well). It's worked very well.