Hi everyone, I would like to start a discussion[1] about how to make Expression string serializable and deserializable. Expression is the general interface for all kinds of expressions in Flink Table API & SQL, it represents a logical tree for producing a computation result. In FLIP-66[2] and FLIP-70[3], we introduced watermark and computed column syntax in DDL. The watermark strategy and computed column are both represented in Expression. In order to persist watermark and computed column information in catalog, we need to figure out how to persist and restore Expression.
FLIP-80: https://docs.google.com/document/d/1LxPEzbPuEVWNixb1L_USv0gFgjRMgoZuMsAecS_XvdE/edit?usp=sharing Thanks for any feedback! Best, Jark [1]: https://docs.google.com/document/d/1LxPEzbPuEVWNixb1L_USv0gFgjRMgoZuMsAecS_XvdE/edit?usp=sharing [2]: https://cwiki.apache.org/confluence/display/FLINK/FLIP-66%3A+Support+time+attribute+in+SQL+DDL [3]: https://cwiki.apache.org/confluence/display/FLINK/FLIP-70%3A+Flink+SQL+Computed+Column+Design
