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From "hongyuhong (JIRA)" <j...@apache.org>
Subject [jira] [Created] (FLINK-6233) Support rowtime inner equi-join between two streams in the SQL API
Date Fri, 31 Mar 2017 09:40:41 GMT
hongyuhong created FLINK-6233:

             Summary: Support rowtime inner equi-join between two streams in the SQL API
                 Key: FLINK-6233
                 URL: https://issues.apache.org/jira/browse/FLINK-6233
             Project: Flink
          Issue Type: Sub-task
          Components: Table API & SQL
            Reporter: hongyuhong
            Assignee: hongyuhong

The goal of this issue is to add support for inner equi-join on proc time streams to the SQL
Queries similar to the following should be supported:
SELECT o.rowtime , o.productId, o.orderId, s.rowtime AS shipTime 
FROM Orders AS o 
JOIN Shipments AS s 
ON o.orderId = s.orderId 
AND o.rowtime BETWEEN s.rowtime AND s.rowtime + INTERVAL '1' HOUR;

The following restrictions should initially apply:
* The join hint only support inner join
* The ON clause should include equi-join condition
* The time-condition {{o.rowtime BETWEEN s.rowtime AND s.rowtime + INTERVAL '1' HOUR}} only
can use rowtime that is a system attribute, the time condition only support bounded time range
like {{o.rowtime BETWEEN s.rowtime - INTERVAL '1' HOUR AND s.rowtime + INTERVAL '1' HOUR}},
not support unbounded like {{o.rowtime > s.rowtime }},  and  should include both two stream's
rowtime attribute, {{o.rowtime between rowtime () and rowtime () + 1}} should also not be

An row-time streams join will not be able to handle late data, because this would mean in
insert a row into a sorted order shift all other computations. This would be too expensive
to maintain. Therefore, we will throw an error if a user tries to use an row-time stream join
with late data handling.

This issue includes:
* Design of the DataStream operator to deal with stream join
* Translation from Calcite's RelNode representation (LogicalJoin). 

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