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https://issues.apache.org/jira/browse/FLINK-3850?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15815389#comment-15815389
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ASF GitHub Bot commented on FLINK-3850:
---------------------------------------

Github user twalthr commented on the issue:

    https://github.com/apache/flink/pull/3040
  
    I will also take a look at it soon. Unfortunetly, the build failed. Could 
you have a look at it? I also recommend to change the `TableProgramsTestBase` 
from `TestExecutionMode.COLLECTION` to `TestExecutionMode.CLUSTER` temporarily 
because I'm not sure if the properties are considered in collection execution.


> Add forward field annotations to DataSet operators generated by the Table API
> -----------------------------------------------------------------------------
>
>                 Key: FLINK-3850
>                 URL: https://issues.apache.org/jira/browse/FLINK-3850
>             Project: Flink
>          Issue Type: Improvement
>          Components: Table API & SQL
>            Reporter: Fabian Hueske
>            Assignee: Nikolay Vasilishin
>
> The DataSet API features semantic annotations [1] to hint the optimizer which 
> input fields an operator copies. This information is valuable for the 
> optimizer because it can infer that certain physical properties such as 
> partitioning or sorting are not destroyed by user functions and thus generate 
> more efficient execution plans.
> The Table API is built on top of the DataSet API and generates DataSet 
> programs and code for user-defined functions. Hence, it knows exactly which 
> fields are modified and which not. We should use this information to 
> automatically generate forward field annotations and attach them to the 
> operators. This can help to significantly improve the performance of certain 
> jobs.
> [1] 
> https://ci.apache.org/projects/flink/flink-docs-release-1.0/apis/batch/index.html#semantic-annotations



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