Hi everyone,
I would like to start a discussion about introducing the concept of
"System Columns" in SQL and Table API.
The subject sounds bigger than it actually is. Luckily, Flink SQL
already exposes the concept of metadata columns. And this proposal is
just a slight adjustment for how metadata columns can be used as system
columns.
The biggest problem of metadata columns currently is that a catalog
implementation can't provide them by default because they would affect
`SELECT *` when adding another one.
Looking forward to your feedback on FLIP-348:
https://cwiki.apache.org/confluence/display/FLINK/FLIP-348%3A+Support+System+Columns+in+SQL+and+Table+API
Thanks,
Timo
