Thanks for the discussion, JING ZHANG. I like the first proposal since it
is simple and consistent with dataStream API. It is helpful to add more
docs about the special late case in WindowAggregate. Also, I expect the
more flexible emit strategies later.
Jark Wu 于2021年7月2日周五 上午10:33写道：
> Sorry,
Sorry, I made a typo above. I mean I prefer proposal (1) that
only needs to set `table.exec.emit.allow-lateness` to handle late events.
`table.exec.emit.late-fire.delay` can be optional which is 0s by default.
`table.exec.state.ttl` will not affect window state anymore, so window state
is still
Thanks Jing for bringing up this topic,
The emit strategy configs are annotated as Experiential and not public on
documentations.
However, I see this is a very useful feature which many users are looking
for.
I have posted these configs for many questions like "how to handle late
events in SQL".
When WindowAggregate works upon Changelog which contains update messages,
UPDATE BEFORE message may be dropped as a late message. [1]
In order to handle late UB message, user needs to set *all* the following 3
parameters:
(1) enable late fire by setting
table.exec.emit.late-fire.enabled : true
