[jdelman]

The ability to express joins in terms of SQL with Estuary is pretty cool. Flink can do a lot of what is described in this post, but you have to set up a lot of intermediate structures, write a lot of Java/Scala, and store your state as protos to support backwards compatibility. Abstracting all of that away would be a huge time saver, but I imagine not having fine grained control over the results and join methods could be frustrating.

[fiddlerwoaroof]

Flink does have a SQL join now that you can make work. Streaming joins remain a hard problem, though and, imo, SQL doesn’t map nicely onto streaming systems.