Thanks for your example, Maciej
I can explain more about the design.
> Let's have events.
> S1, id1, v1, 1
> S2, id1, v2, 1
>
> Nothing is happening as none of the streams have reached the watermark.
> Now let's add
> S2, id2, v2, 101
> This should trigger join for id1 because we have all the kno
Hi Leonard,
Let's assume we have two streams.
S1 - id, value1, ts1 with watermark = ts1 - 1
S2 - id, value2, ts2 with watermark = ts2 - 1
Then we have following interval join
SELECT id, value1, value2, ts1 FROM S1 JOIN S2 ON S1.id = S2.id and
ts1 between ts2 - 1 and ts2
Let's have events.
stream,
Hello, Maciej
> I agree the watermark should pass on versioned table side, because
> this is the only way to know which version of record should be used.
> But if we mimics behaviour of interval join then main stream watermark
> could be skipped.
IIRC, rowtime interval join requires the watermark
Hi Shengkai,
Thanks for the answer. The question is do we need to determine if an
event in the main stream is late.
Let's look at interval join - event is emitted as soon as there is a
match between left and right stream.
I agree the watermark should pass on versioned table side, because
this is th
Hi, maverick.
The watermark is used to determine the message is late or early. If we only
use the watermark on versioned table side, we have no means to determine
whether the event in the main stream is ready to emit.
Best,
Shengkai
maverick 于2021年4月26日周一 上午2:31写道：
> Hi,
> I'm curious why Even
Hi,
I'm curious why Event Time Temporal Join needs watermarks from both sides to
perform join.
Shouldn't watermark on versioned table side be enough to perform join ?
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