GitHub user hequn8128 opened a pull request:
https://github.com/apache/flink/pull/5273
[FLINK-8400] [table] Use the lexicographic smallest attribute as the common
group id when extract unique key
## What is the purpose of the change
`UniqueKeyExtractor` will return a tuple, the first element is the name of
a key field, the second is a group name that is shared by all equivalent key
fields. The group names are used to identify same keys, for example: select('pk
as pk1, 'pk as pk2), both pk1 and pk2 belong to the same group, i.e., pk1. Here
we use the lexicographic smallest attribute as the common group id.
Currently, when extract unique keys from `DataStreamCalc`, the generated
group id is not the lexicographic smallest attribute. This pr will fix this bug.
## Brief change log
- Use lexicographic smallest attribute as group id when extract unique
key for `DataStreamCalc`
- Add test to check whether group id is the lexicographic smallest
attribute.
## Verifying this change
This change added tests and can be verified as follows:
- Add test to check whether group id is the lexicographic smallest
attribute
## 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): (no)
- Anything that affects deployment or recovery: JobManager (and its
components), Checkpointing, Yarn/Mesos, ZooKeeper: (no)
- The S3 file system connector: (no)
## Documentation
- Does this pull request introduce a new feature? (no)
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/hequn8128/flink 6904_groupid
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/flink/pull/5273.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 #5273
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commit 53716b34ab7a9eab1362b07783a8a64fcc732757
Author: åé¿ <hequn.chq@...>
Date: 2018-01-10T07:48:19Z
[FLINK-6094] [table] use the lexicographic smallest attribute as the common
group id
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