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https://issues.apache.org/jira/browse/FLINK-5657?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15853890#comment-15853890
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Yuhong Hong commented on FLINK-5657:
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Hi Fabian, I'm interested in implementing this issue.
As unbounded record, we can just keep a reducing result per group,
so we can add an DataStreamGroupReduce similar to StreamGroupedReduce,
and it's a simplified GlobalWindow which no keeping the records to reduce
memory.
Another problem is that parse the sql to relnode. I agree with @radu that use
the LogicalWindow,
but if only use volcanoplanner, it seems that the optimiztion
ProjectToWindowRule can not effect.
I expect we can use both hep planner and volcanoplanner like Samza.
I'm not sure if it's a good solution, hope some suggestion.
> Add processing time OVER RANGE BETWEEN UNBOUNDED PRECEDING aggregation to SQL
> -----------------------------------------------------------------------------
>
> Key: FLINK-5657
> URL: https://issues.apache.org/jira/browse/FLINK-5657
> Project: Flink
> Issue Type: Sub-task
> Components: Table API & SQL
> Reporter: Fabian Hueske
> Assignee: sunjincheng
>
> 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 UNBOUNDED
> PRECEDING AND CURRENT ROW) AS sumB,
> MIN(b) OVER (PARTITION BY c ORDER BY procTime() RANGE BETWEEN UNBOUNDED
> 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.
> - bounded PRECEDING is not supported (see FLINK-5654)
> - 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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