Hacker News Reader

I don't really understand why author treats Flink datastream API as "high temporal locality" and "can't express our running example". Windowing operators provided by Flink are just an one way of using datastream, and you can easily express any operations you want using something like KeyedProcessFunction and manually manipulating the state.

View on HN

> you can easily express any operations you want

That's true in that the table api itself is built on top of the datastream api. But to run the example you'd have to implement your own joins and retraction-aware aggregates and then we'd be testing the consistency properties of that implementation, not of the datastream api itself, and we might as well test a mature implementation like the table api instead.

Yes, if you want to perfectly match SQL semantics. It's not only way of thinking about data though.

Reply on news.ycombinator.com