Calcite for simple embedded event processing

[Simeon Zverinski]

Hi all,

I'm pretty new to Calcite and understood that it's mainly supposed to be 
used for building data processing engines. I've also found in 
examples/unit tests that Calcite has its own engine as well. It looks 
like this engine doesn't implement all the features though. For example, 
Streaming Group By is not yet supported 
(https://issues.apache.org/jira/browse/CALCITE-1345) and also not all 
time grouping functions are fully implemented, such as TUMBLE. Anyway I 
found this small engine to be very useful for implementing small 
embedded solutions when you don't want to introduce dependencies on 
something big such as Flink.

What do you think about using pure Calcite for embedded solutions? Any 
hints on how to implement missing functions?

Thanks,

Simeon