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https://issues.apache.org/jira/browse/FLINK-5315?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16568153#comment-16568153
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Hequn Cheng commented on FLINK-5315:
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Hi [~walterddr] Distinct of Table is not a modifier. It is an operator. The
output are different for
{code:java}
table.select('a, 'b).distinct
{code}
and
{code:java}
table.distinct.select('a, 'b)
{code}
For the distinct of agg. It is better to put distinct together with agg. You
can treat {{agg.distinct}} as a whole, i.e.
{{'a.aggwithdistinct}}/{{aggwithdistinct(a)}}.
What do you think?
> Support distinct aggregations in table api
> ------------------------------------------
>
> Key: FLINK-5315
> URL: https://issues.apache.org/jira/browse/FLINK-5315
> Project: Flink
> Issue Type: Sub-task
> Components: Table API & SQL
> Reporter: Kurt Young
> Assignee: Rong Rong
> Priority: Major
>
> Support distinct aggregations in Table API in the following format:
> For Expressions:
> {code:scala}
> 'a.count.distinct // Expressions distinct modifier
> {code}
> For User-defined Function:
> {code:scala}
> singleArgUdaggFunc.distinct('a) // FunctionCall distinct modifier
> multiArgUdaggFunc.distinct('a, 'b) // FunctionCall distinct modifier
> {code}
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