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hongyuhong commented on FLINK-6233: ----------------------------------- Hi [~fhueske], the reason i think we need to keep the order is if the next operator is in update mode, we should use the latest one to replace the past one. such as: suppose B1(Time:10) is arrive later than B2(Time:12), if ignore order, the result will be: A1B2 then A1B1, if output as timestamp order, the result will be A1B1 then A1B2 i think it should use A1B2 to replace A1B1 but not A1B1 to replace A1B2. if we do not need to guarantee the order, then i think we can just output when processElement, no need to wait until a watermark come. What do you think? > 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 interface. > Queries similar to the following should be supported: > {code} > 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; > {code} > 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 supported. > 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). -- This message was sent by Atlassian JIRA (v6.3.15#6346)