[
https://issues.apache.org/jira/browse/FLINK-6228?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15977659#comment-15977659
]
ASF GitHub Bot commented on FLINK-6228:
---------------------------------------
Github user fhueske commented on a diff in the pull request:
https://github.com/apache/flink/pull/3743#discussion_r112455555
--- Diff:
flink-libraries/flink-table/src/main/scala/org/apache/flink/table/api/table.scala
---
@@ -810,6 +810,47 @@ class Table(
new WindowedTable(this, window)
}
+ /**
--- End diff --
Extend docs to
```
/**
* Defines over-windows on the records of a table.
*
* An over-window defines for each record an interval of records over
which aggregation
* functions can be computed.
*
* Example:
*
* {{{
* table
* .window(Over partitionBy 'c orderBy 'rowTime preceding 10.seconds
as 'ow)
* .select('c, 'b.count over 'ow, 'e.sum over 'ow)
* }}}
*
* __Note__: Computing over window aggregates on a streaming table is
only a parallel operation
* if the window is partititioned. Otherwise, the whole stream will be
processed by a single
* task, i.e., with parallelism 1.
*
* __Note__: Over-windows for batch tables are currently not supported.
*
* @param overWindows windows that specify the record interval over
which aggregations are
* computed.
* @return An OverWindowedTable to specify the aggregations.
*/
```
> Integrating the OVER windows in the Table API
> ---------------------------------------------
>
> Key: FLINK-6228
> URL: https://issues.apache.org/jira/browse/FLINK-6228
> Project: Flink
> Issue Type: Sub-task
> Components: Table API & SQL
> Reporter: sunjincheng
> Assignee: sunjincheng
>
> Syntax:
> {code}
> table
> .overWindows(
> (Rows|Range [ partitionBy value_expression , ... [ n ]] [ orderBy
> order_by_expression]
> (preceding
> UNBOUNDED|value_specification.(rows|milli|second|minute|hour|day|month|year)|CURRENTROW)
> [following
> UNBOUNDED|value_specification.(rows|milli|second|minute|hour|day|month|year)|CURRENTROW]
> as alias,...[n])
> )
> .select( [col1,...[n]], (agg(col1) OVER overWindowAlias, … [n])
> {code}
> Implement restrictions:
> * 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 Before the
> [FLINK-5884|https://issues.apache.org/jira/browse/FLINK-5884] implementation
> orderBy may only have ‘rowtime/’proctime(for stream)/‘specific-time-field(for
> batch).
> * FOLLOWING is not supported.
> User interface design document [See |
> https://docs.google.com/document/d/13Z-Ovx3jwtmzkSweJyGkMy751BouhuJ29Y1CTNZt2DI/edit#]
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