[jira] [Commented] (FLINK-5433) initiate function of Aggregate does not take effect for DataStream aggregation

["Shaoxuan Wang (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/FLINK-5433?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15814399#comment-15814399 ] 

Shaoxuan Wang commented on FLINK-5433:
--------------------------------------

It seems initiate function has only been used in AggregateReduceCombineFunction and AggregateReduceGroupFunction. DataStream with Incremental Aggregation will not be able to get a chance to execute initiate.

> initiate function of Aggregate does not take effect for DataStream aggregation
> ------------------------------------------------------------------------------
>
>                 Key: FLINK-5433
>                 URL: https://issues.apache.org/jira/browse/FLINK-5433
>             Project: Flink
>          Issue Type: Bug
>          Components: Table API & SQL
>            Reporter: Shaoxuan Wang
>
> The initiate function of Aggregate works for dataset aggregation, but does not work for DataStream aggregation.
> For instance, when giving an initial value, say 2, for CountAggregate. The result of dataset aggregate will take this change into account, but dataStream aggregate will not.
> {code}
> class CountAggregate extends Aggregate[Long] {
>   override def initiate(intermediate: Row): Unit = {
>     intermediate.setField(countIndex, 2L)
>   }
> }
> {code}
> The output for dataset test(testWorkingAggregationDataTypes) will result in
> .select('_1.avg, '_2.avg, '_3.avg, '_4.avg, '_5.avg, '_6.avg, '_7.count)
>  expected: [1,1,1,1,1.5,1.5,2]
>  received: [1,1,1,1,1.5,1.5,4] （the result of last count aggregate is bigger than expect value by 2, as expected）
> But the output for datastream test(testProcessingTimeSlidingGroupWindowOverCount) will remain the same：
> .select('string, 'int.count, 'int.avg)
> Expected :List(Hello world,1,3, Hello world,2,3, Hello,1,2, Hello,2,2, Hi,1,1)
> Actual   :MutableList(Hello world,1,3, Hello world,2,3, Hello,1,2, Hello,2,2, Hi,1,1)



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