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https://issues.apache.org/jira/browse/FLINK-5695?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15850965#comment-15850965
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sunjincheng commented on FLINK-5695:
------------------------------------
Hi, [~fhueske] , Yes, I would like to explain my purpose:
There are only one "select" operation for WindowGroupedTable.
GroupedTable also has only one "select" operation, and all of them are
generated by "groupBy" operation (WindowedTable.groupBy | Table.groupBy). The
only difference is groupBy's keys, The keys of "WindowedTable" "GroupBy"
operation contain the "window", for the user is just add window-related fields
in the table, such as windowStrat and windowEnd. "GroupedTable.select" and
"WindowGroupedTable.select" semantics is no different, GroupedTable type easy
to understand by users, and "GroupedTable" should have all of the
characteristics which "WindowGroupedTable" have, so I personally feel should be
removed "WindowGroupedTable" type.
> 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]
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