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https://issues.apache.org/jira/browse/FLINK-6261?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15958710#comment-15958710
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ASF GitHub Bot commented on FLINK-6261:
---------------------------------------

Github user fhueske commented on the issue:

    https://github.com/apache/flink/pull/3675
  
    Hi @haohui, I updated the PR and refactored the rule into an abstract class 
that is extended by a rule for datastream and another one for dataset.
    
    **Please note**: I also removed support for `GROUP BY FLOOR/CEIL` on 
streams. My motivation is the following:
    - it can be expressed with `TUMBLE` (which is even more expressive)
    - We will add support for "non-windowed" aggregations (see PR #3646 by 
@shaoxuan-wang ) which can include the `GROUP BY FLOOR/CEIL` case. These 
aggregations will compute the same result but behave differently at runtime. 
Instead of collecting data and emitting a final result, they will be 
incrementally computed and send out more updates. I think the behavior of 
system is more predictable if we only translate Calcite's group window 
functions into DataStream group windows and all other grouped aggregates into 
non-windowed aggregates. We target the non-windowed aggregates for the next 
release.
    - It will make the translation easier. The pattern matching of `FLOOR/CEIL` 
seems a bit fragile to me. I like Calcite's group window functions more.
    
    Please let me know what you think about this change and if you have 
concerns.
    
    Best, Fabian


> Add support for TUMBLE, HOP, SESSION to batch SQL
> -------------------------------------------------
>
>                 Key: FLINK-6261
>                 URL: https://issues.apache.org/jira/browse/FLINK-6261
>             Project: Flink
>          Issue Type: Sub-task
>          Components: Table API & SQL
>    Affects Versions: 1.3.0
>            Reporter: Fabian Hueske
>            Assignee: Fabian Hueske
>
> Add support for the TUMBLE, HOP, SESSION keywords for batch SQL. 



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