PipelineDB is pretty interesting for time-series data. It takes an approach to processing the data as it comes in, and storing aggregates or pre-aggregates over

PipelineDB is pretty interesting for time-series data. It takes an approach to processing the data as it comes in, and storing aggregates or pre-aggregates over time series. I haven't followed the latest, but as of a few years ago much of the approach was similar to some research out of UC Berkeley from about 10 years ago. You can find the paper that talks about that work (TelegraphCQ CQ for continuous query) at http://db.csail.mit.edu/madden/html/TCQcidr03.pdf http://db.csail.mit.edu/madden/html/TCQcidr03.pdf. Definitely an interesting read if you're into technical papers and databases.