[ 
https://issues.apache.org/jira/browse/FLINK-5695?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15848638#comment-15848638
 ] 

Fabian Hueske commented on FLINK-5695:
--------------------------------------

Hi [~sunjincheng121], I am not sure how this change would improve the Table 
API. IMO, it only merges the functionality of two classes and adds a condition 
to decide which translation path to take.

I do not see the {{GroupWindowedTable}} as a problem. Instead it allows to 
present the user more accurate documentation (via Java / Scala Docs), for 
example to explain how the window alias can be used to access the window 
{{start}} and {{end}} properties.
By merging the functionality of {{GroupedTable.select()}} and 
{{GroupWindowedTable.select()}} we lose that.

Can you explain your motivation for this change?

Thanks, Fabian

> Optimize table type systems based on database semantics
> -------------------------------------------------------
>
>                 Key: FLINK-5695
>                 URL: https://issues.apache.org/jira/browse/FLINK-5695
>             Project: Flink
>          Issue Type: Sub-task
>          Components: Table API & SQL
>            Reporter: sunjincheng
>            Assignee: sunjincheng
>
> Optimize table type systems based on database semantics.As follows:
> {code}
>              groupBy
>          -------------------->
> Table                             GroupedTable
>   ∧   <--------------------           ∧
>    |         select&agg                |
>    |                                           |
>    | where                                |
>    | select                                | groupBy
>    | agg                                   |
>    | ...                                      |
>    |             window                 |
>   ∨     --------------------->     
>  Table                            WindowedTable
>           <---------------------
>               select&over
> {code}
> What do you think? [~fhueske] 



--
This message was sent by Atlassian JIRA
(v6.3.15#6346)

Reply via email to