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https://issues.apache.org/jira/browse/FLINK-6233?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16194786#comment-16194786
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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_r143231150
--- Diff:
flink-libraries/flink-table/src/test/scala/org/apache/flink/table/runtime/stream/sql/JoinITCase.scala
---
@@ -102,5 +117,154 @@ class JoinITCase extends StreamingWithStateTestBase {
env.execute()
}
+ /** test rowtime inner join **/
+ @Test
+ def testRowTimeInnerJoin(): Unit = {
+ val env = StreamExecutionEnvironment.getExecutionEnvironment
+ val tEnv = TableEnvironment.getTableEnvironment(env)
+ env.setStateBackend(getStateBackend)
+ env.setStreamTimeCharacteristic(TimeCharacteristic.EventTime)
+ StreamITCase.clear
+ env.setParallelism(1)
+
+ val sqlQuery =
+ """
+ |SELECT t2.a, t2.c, t1.c
+ |FROM T1 as t1 join T2 as t2 ON
+ | t1.a = t2.a AND
+ | t1.rt BETWEEN t2.rt - INTERVAL '5' SECOND AND
+ | t2.rt + INTERVAL '6' SECOND
+ |""".stripMargin
+
+ val data1 = new mutable.MutableList[(Int, Long, String, Long)]
--- End diff --
If I understand correctly, this problem was caused by the different
semantics of `Null` in SQL and other common languages (i.e., `Null =? Null`).
We transform the equi-conditions to a `keyBy` operation and maybe rows with
`Null` keys are mapped to the same group, thus being taken as identical?
> 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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