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https://issues.apache.org/jira/browse/FLINK-5654?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15933673#comment-15933673
 ] 

ASF GitHub Bot commented on FLINK-5654:
---------------------------------------

Github user fhueske commented on a diff in the pull request:

    https://github.com/apache/flink/pull/3550#discussion_r107023660
  
    --- Diff: 
flink-libraries/flink-table/src/main/scala/org/apache/flink/table/runtime/aggregate/DataStreamProcTimeAggregateWindowFunction.scala
 ---
    @@ -0,0 +1,108 @@
    +/*
    + * Licensed to the Apache Software Foundation (ASF) under one
    + * or more contributor license agreements.  See the NOTICE file
    + * distributed with this work for additional information
    + * regarding copyright ownership.  The ASF licenses this file
    + * to you under the Apache License, Version 2.0 (the
    + * "License"); you may not use this file except in compliance
    + * with the License.  You may obtain a copy of the License at
    + *
    + *     http://www.apache.org/licenses/LICENSE-2.0
    + *
    + * Unless required by applicable law or agreed to in writing, software
    + * distributed under the License is distributed on an "AS IS" BASIS,
    + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    + * See the License for the specific language governing permissions and
    + * limitations under the License.
    + */
    +package org.apache.flink.table.runtime.aggregate
    +
    +import java.lang.Iterable
    +
    +import org.apache.flink.api.java.tuple.Tuple
    +import org.apache.flink.types.Row
    +import org.apache.flink.configuration.Configuration
    +import 
org.apache.flink.streaming.api.functions.windowing.RichWindowFunction
    +import org.apache.flink.streaming.api.windowing.windows.Window
    +import org.apache.flink.util.Collector
    +import org.apache.flink.table.functions.AggregateFunction
    +import org.apache.flink.table.functions.Accumulator
    +
    +/**
    +  * Computes the final aggregate value from incrementally computed 
aggreagtes.
    +  *
    +  * @param aggregates The aggregates to be computed
    +  * @param aggFields the fields on which to apply the aggregate.
    +  * @param forwardedFieldCount The fields to be carried from current row.
    +  */
    +class DataStreamProcTimeAggregateWindowFunction[W <: Window](
    +     private val aggregates: Array[AggregateFunction[_]],
    +     private val aggFields: Array[Int],
    +     private val forwardedFieldCount: Int)
    +  extends RichWindowFunction[Row, Row, Tuple, W] {
    +
    +private var output: Row = _
    +private var accumulators: Row= _
    +
    +  override def open(parameters: Configuration): Unit = {
    +     output = new Row(forwardedFieldCount + aggregates.length)
    +     accumulators = new Row(aggregates.length)
    +     var i = 0
    +     while (i < aggregates.length) {
    +        accumulators.setField(i, aggregates(i).createAccumulator())
    +        i = i + 1
    --- End diff --
    
    `i += 1`


> Add processing time OVER RANGE BETWEEN x PRECEDING aggregation to SQL
> ---------------------------------------------------------------------
>
>                 Key: FLINK-5654
>                 URL: https://issues.apache.org/jira/browse/FLINK-5654
>             Project: Flink
>          Issue Type: Sub-task
>          Components: Table API & SQL
>            Reporter: Fabian Hueske
>            Assignee: radu
>
> The goal of this issue is to add support for OVER RANGE aggregations on 
> processing time streams to the SQL interface.
> Queries similar to the following should be supported:
> {code}
> SELECT 
>   a, 
>   SUM(b) OVER (PARTITION BY c ORDER BY procTime() RANGE BETWEEN INTERVAL '1' 
> HOUR PRECEDING AND CURRENT ROW) AS sumB,
>   MIN(b) OVER (PARTITION BY c ORDER BY procTime() RANGE BETWEEN INTERVAL '1' 
> HOUR PRECEDING AND CURRENT ROW) AS minB
> FROM myStream
> {code}
> The following restrictions should initially apply:
> - All OVER clauses in the same SELECT clause must be exactly the same.
> - The PARTITION BY clause is optional (no partitioning results in single 
> threaded execution).
> - The ORDER BY clause may only have procTime() as parameter. procTime() is a 
> parameterless scalar function that just indicates processing time mode.
> - UNBOUNDED PRECEDING is not supported (see FLINK-5657)
> - FOLLOWING is not supported.
> The restrictions will be resolved in follow up issues. If we find that some 
> of the restrictions are trivial to address, we can add the functionality in 
> this issue as well.
> This issue includes:
> - Design of the DataStream operator to compute OVER ROW aggregates
> - Translation from Calcite's RelNode representation (LogicalProject with 
> RexOver expression).



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