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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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