[BenoitP]

I'm very hopeful for approaches that model around this need from the ground up. Big Data distributed stream processing frameworks like Spark or Flink allow for standing SQL queries that are incrementally build; and you can even subscribe to react to the results.

There are other initiatives for plugging it on existing RDBMSs, like Noria [1] for MySQL. It allows for subscribing to changes; and also for lazy evaluation of the materializing view rows, keeping them in cache for later.

[1] https://github.com/mit-pdos/noria/blob/master/README.md