Hi Wenhui, Thanks for bringing the topics up. Both make sense to me. For higher-order functions, I'd suggest you come up with a list of things you'd like to add. Overall, Flink SQL is weak in handling complex types. Ideally we should have a doc covering the gaps and provide a roadmap for enhancement. It would be great if you can broaden the topic a bit.
Thanks, Xuefu ------------------------------------------------------------------ Sender:winifred.wenhui.t...@gmail.com <winifred.wenhui.t...@gmail.com> Sent at:2018 Dec 3 (Mon) 16:13 Recipient:dev <dev@flink.apache.org> Subject:[DISCUSS] Support Higher-order functions in Flink sql Hello all， Spark 2.4.0 was released last month. I noticed that Spark 2.4 “Add a lot of new built-in functions, including higher-order functions, to deal with complex data types easier.”[1] I wonder if it's necessary for Flink to add higher-order functions to enhance it's ability. By the way, I found that if we wants to enhance the functionality of Flink sql, we often need to modify Calcite. It may be a little inconvenient，so may be we can extend Calcite core parser in Flink to deal with some non-standard SQL syntax, as mentioned in Flink SQL DDL Design[2]. Look forward to your feedback. Best, Wen-hui Tang [1] https://issues.apache.org/jira/browse/SPARK-23899 [2] https://docs.google.com/document/d/1TTP-GCC8wSsibJaSUyFZ_5NBAHYEB1FVmPpP7RgDGBA/edit# Winifred-wenhui Tang
