If you need an outer join, the only solution is to convert the table into a
retraction stream and correctly handle the retraction messages.
Btw. even then this might not perform as you would like it to be.
The query will store all input tables completely in state. So you might run
out of space soon
Thanks so much for your answer , but then how should I perform such as
comparison ? Which options do we have ?
Thanks
Le mer. 24 juill. 2019 10:01 p.m., Ruidong Li a
écrit :
> Hi, it's because the Outer Joins will generate retractions, consider the
> behavior of Left Outer Join
>
> 1. left reco
Hi, it's because the Outer Joins will generate retractions, consider the
behavior of Left Outer Join
1. left record arrives, no matched right record, so +(left, null) will be
generated.
2 right record arrives, the previous result should be retracted, so
-(left, null) and +(left, right) will be
