GitHub user walterddr opened a pull request:
https://github.com/apache/flink/pull/5940
[FLINK-8690][table]Support DistinctAgg on DataStream
## What is the purpose of the change
* Allow FlinkLogicalAggregate to support distinct aggregations on
DataStream, while keeping DataSet to decompose distinct aggs into GROUP BY
follow by normal aggregates.
## Brief change log
- Moved `AggregateExpandDistinctAggregatesRule.JOIN` to
`DATASET_NORM_RULES`
- Enabled `DataStreamGroupWindowAggregate` to support distinct agg while
maintaining unsupported for `[DataStream/DataSet]GroupAggregate`.
- Fixed typo in codegen for distinct aggregate when merge
- Fixed a possible codegen test error for `UNION ALL`.
## Verifying this change
- Unit-test are added for `DistinctAggregateTest`
- Added ITCase for distinct group window agg
## Does this pull request potentially affect one of the following parts:
- Dependencies (does it add or upgrade a dependency): no
- The public API, i.e., is any changed class annotated with
`@Public(Evolving)`: no
- The serializers: no
- The runtime per-record code paths (performance sensitive): yes (codegen)
- Anything that affects deployment or recovery: no
- The S3 file system connector: no
## Documentation
- Does this pull request introduce a new feature? yes
- If yes, how is the feature documented? not yet, should we put in
`Aggregate` section or `Group Window` section? inputs are highly appreciated.
Also distinct over aggregate is bug-fixed in FLINK-8689 but not documented.
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/walterddr/flink FLINK-8690
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/flink/pull/5940.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #5940
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commit c517821d13341ae10b5d47acdbd0cc7d5bbe38b7
Author: Rong Rong <rongr@...>
Date: 2018-04-28T15:59:12Z
moving AggregateExpandDistinctAggregatesRule.JOIN to DATASET_NORM_RULES,
and enabled distinct aggregate support for window aggregate over datastream
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