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Posted to issues@calcite.apache.org by "Rheet Wong (JIRA)" <ji...@apache.org> on 2017/09/21 14:50:00 UTC
[jira] [Created] (CALCITE-1990) Make RelDistribution to extends
RelMultipleTrait
Rheet Wong created CALCITE-1990:
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Summary: Make RelDistribution to extends RelMultipleTrait
Key: CALCITE-1990
URL: https://issues.apache.org/jira/browse/CALCITE-1990
Project: Calcite
Issue Type: Bug
Reporter: Rheet Wong
Assignee: Julian Hyde
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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