[jira] [Commented] (FLINK-10845) Support DISTINCT aggregates for batch

["ASF GitHub Bot (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/FLINK-10845?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16708820#comment-16708820 ] 

ASF GitHub Bot commented on FLINK-10845:
----------------------------------------

twalthr commented on a change in pull request #7079: [FLINK-10845][table] Support multiple different DISTINCT aggregates for batch
URL: https://github.com/apache/flink/pull/7079#discussion_r238696433
 
 

 ##########
 File path: flink-libraries/flink-table/src/main/scala/org/apache/flink/table/codegen/calls/ScalarOperators.scala
 ##########
 @@ -191,7 +191,17 @@ object ScalarOperators {
           )
         )
     }
-  }  
+  }
+
+  def generateDistinctFrom(
+      nullCheck: Boolean,
+      left: GeneratedExpression,
+      right: GeneratedExpression)
+    : GeneratedExpression = {
+    val newleft = left.copy(nullTerm = GeneratedExpression.NEVER_NULL)
 
 Review comment:
   This looks not correct to me. By setting the expression to never null, you basically compare the default values of expressions. Long has `0L` for example. For example, a `0 IS NOT DISTINCT FROM NULL` might return `true`.

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> Support DISTINCT aggregates for batch
> -------------------------------------
>
>                 Key: FLINK-10845
>                 URL: https://issues.apache.org/jira/browse/FLINK-10845
>             Project: Flink
>          Issue Type: New Feature
>          Components: Table API & SQL
>            Reporter: Timo Walther
>            Assignee: xueyu
>            Priority: Major
>              Labels: pull-request-available
>
> Currently, we support distinct aggregates for streaming. However, executing the same query on batch like the following test:
> {code}
>     val env = ExecutionEnvironment.getExecutionEnvironment
>     val tEnv = TableEnvironment.getTableEnvironment(env)
>     val sqlQuery =
>       "SELECT b, " +
>       "  SUM(DISTINCT (a / 3)), " +
>       "  COUNT(DISTINCT SUBSTRING(c FROM 1 FOR 2))," +
>       "  COUNT(DISTINCT c) " +
>       "FROM MyTable " +
>       "GROUP BY b"
>     val data = new mutable.MutableList[(Int, Long, String)]
>     data.+=((1, 1L, "Hi"))
>     data.+=((2, 2L, "Hello"))
>     data.+=((3, 2L, "Hello world"))
>     data.+=((4, 3L, "Hello world, how are you?"))
>     data.+=((5, 3L, "I am fine."))
>     data.+=((6, 3L, "Luke Skywalker"))
>     data.+=((7, 4L, "Comment#1"))
>     data.+=((8, 4L, "Comment#2"))
>     data.+=((9, 4L, "Comment#3"))
>     data.+=((10, 4L, "Comment#4"))
>     data.+=((11, 5L, "Comment#5"))
>     data.+=((12, 5L, "Comment#6"))
>     data.+=((13, 5L, "Comment#7"))
>     data.+=((14, 5L, "Comment#8"))
>     data.+=((15, 5L, "Comment#9"))
>     data.+=((16, 6L, "Comment#10"))
>     data.+=((17, 6L, "Comment#11"))
>     data.+=((18, 6L, "Comment#12"))
>     data.+=((19, 6L, "Comment#13"))
>     data.+=((20, 6L, "Comment#14"))
>     data.+=((21, 6L, "Comment#15"))
>     val t = env.fromCollection(data).toTable(tEnv).as('a, 'b, 'c)
>     tEnv.registerTable("MyTable", t)
>     tEnv.sqlQuery(sqlQuery).toDataSet[Row].print()
> {code}
> Fails with:
> {code}
> org.apache.flink.table.codegen.CodeGenException: Unsupported call: IS NOT DISTINCT FROM 
> If you think this function should be supported, you can create an issue and start a discussion for it.
> 	at org.apache.flink.table.codegen.CodeGenerator$$anonfun$visitCall$3.apply(CodeGenerator.scala:1027)
> 	at org.apache.flink.table.codegen.CodeGenerator$$anonfun$visitCall$3.apply(CodeGenerator.scala:1027)
> 	at scala.Option.getOrElse(Option.scala:121)
> 	at org.apache.flink.table.codegen.CodeGenerator.visitCall(CodeGenerator.scala:1027)
> 	at org.apache.flink.table.codegen.CodeGenerator.visitCall(CodeGenerator.scala:66)
> 	at org.apache.calcite.rex.RexCall.accept(RexCall.java:107)
> 	at org.apache.flink.table.codegen.CodeGenerator.generateExpression(CodeGenerator.scala:247)
> 	at org.apache.flink.table.plan.nodes.dataset.DataSetJoin.addInnerJoin(DataSetJoin.scala:221)
> 	at org.apache.flink.table.plan.nodes.dataset.DataSetJoin.translateToPlan(DataSetJoin.scala:170)
> 	at org.apache.flink.table.plan.nodes.dataset.DataSetCalc.translateToPlan(DataSetCalc.scala:91)
> 	at org.apache.flink.table.plan.nodes.dataset.DataSetJoin.translateToPlan(DataSetJoin.scala:165)
> 	at org.apache.flink.table.plan.nodes.dataset.DataSetCalc.translateToPlan(DataSetCalc.scala:91)
> 	at org.apache.flink.table.api.BatchTableEnvironment.translate(BatchTableEnvironment.scala:498)
> 	at org.apache.flink.table.api.BatchTableEnvironment.translate(BatchTableEnvironment.scala:476)
> 	at org.apache.flink.table.api.scala.BatchTableEnvironment.toDataSet(BatchTableEnvironment.scala:141)
> 	at org.apache.flink.table.api.scala.TableConversions.toDataSet(TableConversions.scala:50)
> 	at org.apache.flink.table.runtime.stream.sql.SqlITCase.testDistinctGroupBy(SqlITCase.scala:2
> {code}



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