Hey, I have opened a PR for the windowing rework I have been doing in the last couple of weeks. It introduces several new abstractions for the windowing semantics along with optional global/local discretisation logics and greatly improved performance using pre-aggregators
https://github.com/apache/flink/pull/395 I will do some more testing and if I get some thumbs up I would like to merge it soon. This should be a strict improvement over the current logic both in terms of simplicity and performance. (with even more room for easy improvement) Cheers, Gyula
