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https://issues.apache.org/jira/browse/FLINK-6233?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16194746#comment-16194746
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ASF GitHub Bot commented on FLINK-6233:
---------------------------------------
Github user xccui commented on a diff in the pull request:
https://github.com/apache/flink/pull/4625#discussion_r143222605
--- Diff:
flink-libraries/flink-table/src/main/scala/org/apache/flink/table/plan/nodes/datastream/DataStreamWindowJoin.scala
---
@@ -184,4 +229,50 @@ class DataStreamWindowJoin(
.returns(returnTypeInfo)
}
}
+
+ def createRowTimeInnerJoin(
+ leftDataStream: DataStream[CRow],
+ rightDataStream: DataStream[CRow],
+ returnTypeInfo: TypeInformation[CRow],
+ joinFunctionName: String,
+ joinFunctionCode: String,
+ leftKeys: Array[Int],
+ rightKeys: Array[Int]): DataStream[CRow] = {
+
+ val rowTimeInnerJoinFunc = new RowTimeBoundedStreamInnerJoin(
+ leftLowerBound,
+ leftUpperBound,
+ allowedLateness = 0L,
+ leftSchema.typeInfo,
+ rightSchema.typeInfo,
+ joinFunctionName,
+ joinFunctionCode,
+ leftTimeIdx,
+ rightTimeIdx)
+
+ if (!leftKeys.isEmpty) {
+ leftDataStream
+ .connect(rightDataStream)
+ .keyBy(leftKeys, rightKeys)
--- End diff --
Actually, I was quite confused about this condition `!leftKeys.isEmpty`.
Since in `FlinkLogicalJoin.scala`, queries without equi-conditions are blocked,
when will this condition be hold?
> 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: Xingcan Cui
>
> 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).
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