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Posted to issues@calcite.apache.org by "Julian Hyde (Jira)" <ji...@apache.org> on 2019/11/04 16:20:00 UTC

[jira] [Commented] (CALCITE-3473) Getting unique result for table scan should contain key column(s)

    [ https://issues.apache.org/jira/browse/CALCITE-3473?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16966795#comment-16966795 ] 

Julian Hyde commented on CALCITE-3473:
--------------------------------------

This fix has running time exponential in the number of columns (due to powerSet). We can’t do that.

Your tests use the SQL string rather than the RelNode. I suspect that is inconsistent with other metadata tests and won’t be easy to adapt/extend. 


> Getting unique result for table scan should contain key column(s)
> -----------------------------------------------------------------
>
>                 Key: CALCITE-3473
>                 URL: https://issues.apache.org/jira/browse/CALCITE-3473
>             Project: Calcite
>          Issue Type: Improvement
>            Reporter: Wang Yanlin
>            Assignee: Wang Yanlin
>            Priority: Major
>              Labels: pull-request-available
>          Time Spent: 10m
>  Remaining Estimate: 0h
>
> Currently,   *mq.getUniqueKeys()*  for  *TableScan* returns empty.
> However, for table with key column(s) defined, we can refer uniqueness on key column(s), so the result should contain key column(s)



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