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https://issues.apache.org/jira/browse/FLINK-5654?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15949733#comment-15949733
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ASF GitHub Bot commented on FLINK-5654:
---------------------------------------
Github user fhueske commented on the issue:
https://github.com/apache/flink/pull/3641
Sorry, I think did not explain the change correctly.
I did not mean to group multiple record together.
We still emit one row per input row, but given the following input
```
(proc-time, id, a)
(1, a, 1)
(2, b, 2)
(3, c, 3)
(3, d, 4)
(4, e, 5)
```
and the query
```
SELECT id, sum(a) OVER (ORDER BY proctime RANGE BETWEEN 2 PRECEDING AND
CURRENT ROW) FROM x
```
the result would not be
```
(a, 1), (b, 3), (c, 6), (d, 10), (e, 14)
```
and not
```
(a, 1), (b, 3), (c, 10), (d, 10), (e, 14)
```
Because `c` and `d` arrived at the same time, their aggregations need to be
the same.
This is actually also the implementation for event-time OVER RANGE windows.
> 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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