Hi devs, I'm interesting about the new change on FLIP-66 [1], because if I understand correctly, Flink hasn't been having event-time timestamp field (column) as a part of "normal" schema, and FLIP-66 tries to change it.
That sounds as the column may be open for modification, like rename (alias) or some other operations, or even be dropped via projection. Will such operations affect event-time timestamp for the record? If you have an idea about how Spark Structured Streaming works with watermark then you might catch the point. Maybe the question could be reworded as, does the definition of event time timestamp column on DDL only project to the source definition, or it will carry over the entire query and let operator determine such column as event-time timestamp. (SSS works as latter.) I think this is a huge difference, as for me it's like stability vs flexibility, and there're drawbacks on latter (there're also drawbacks on former as well, but computed column may cover up). Thanks in advance! Jungtaek Lim (HeartSaVioR) 1. https://cwiki.apache.org/confluence/display/FLINK/FLIP-66%3A+Support+Time+Attribute+in+SQL+DDL
