Hi everyone,
we (from Flink) are currently discussing how we can express
time-semantics (event-time or processing-time) in a SQL query. The
optimal solution would be to have two system attributes that are part of
every table schema/every row data type. We could then access it like
`SELECT * FROM MyTable ORDER BY rowtime`. However, it should not be part
of the result in an expansion (`*`) and the user should not modify those
attributes (no aliasing, read-only). I had a look into SqlValidator and
there are several lines that contain things like `includeSystemVars` or
`isSystemField` but nothing concrete. Am I right that this feature is
not entirely implemented yet? Which parts would you touch/override to
implement this feature?
Thanks in advance.
Regards,
Timo
