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Posted to issues@calcite.apache.org by "Julian Hyde (JIRA)" <ji...@apache.org> on 2017/11/06 17:04:01 UTC

[jira] [Updated] (CALCITE-1990) Make RelDistribution extend RelMultipleTrait

     [ https://issues.apache.org/jira/browse/CALCITE-1990?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Julian Hyde updated CALCITE-1990:
---------------------------------
    Summary: Make RelDistribution extend RelMultipleTrait  (was: Make RelDistribution to extends RelMultipleTrait)

> Make RelDistribution extend RelMultipleTrait
> --------------------------------------------
>
>                 Key: CALCITE-1990
>                 URL: https://issues.apache.org/jira/browse/CALCITE-1990
>             Project: Calcite
>          Issue Type: Bug
>            Reporter: LeoWangLZ
>            Assignee: Julian Hyde
>   Original Estimate: 0.2h
>  Remaining Estimate: 0.2h
>
> In Distributed System, RelDistribution is used for Exchange or SortExchange. for some operators it may deliver RelDistribution Trait, but some operator like SortedMergeJoin may deliver multiple traits.
> eg:
> {code:java}
> Query:
> select * from T1 join T2 on T1.c1=T2.d1;
> Suppose Plan:
> SortedMergeJoin
>     Exchange(c1)
>         T1(c1)
>     Exchange(d1)
>         T2(d1)
> {code}
> than SortedMergeJoin can deliver RelDistribution(hash\[c1\]) or RelDistribution(hash\[d1\]).
> we can consider RelDistribution extend RelMultipleTrait like RelCollation. 
> EnumerableMergeJoin is the case for RelCollation, and RelDistribution is also fit for SortedMergeJoin in Distributed system



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