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Posted to issues@flink.apache.org by "sunjincheng (JIRA)" <ji...@apache.org> on 2017/02/03 02:47:52 UTC
[jira] [Comment Edited] (FLINK-5695) Optimize table type systems
based on database semantics
[ https://issues.apache.org/jira/browse/FLINK-5695?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15850965#comment-15850965 ]
sunjincheng edited comment on FLINK-5695 at 2/3/17 2:47 AM:
------------------------------------------------------------
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.
Likewise, I think we can write a document that accepts the user if we present the explicit table type to the user. What do you think?
was (Author: sunjincheng121):
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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