Flink's CEP library is a great library for complex event processing, more and more customers are expressing their interests in it. But it also has some limitations that users usually have to write a lot of code even for a very simple pattern match use case as it currently only supports the Java API.
CEP DSLs and SQLs strongly resemble each other. CEP's additional features compared to SQL boil down to pattern detection. So It will be awesome to consolidate CEP and SQL. It makes SQL more powerful to support more usage scenario. And it gives users the ability to easily and quickly to build CEP applications.
The FLIP can be found here:
This is an umbrella issue for the FLIP. We should wait for Calcite 1.13 to start this work.