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https://issues.apache.org/jira/browse/CALCITE-2973?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16838592#comment-16838592
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Ruben Quesada Lopez commented on CALCITE-2973:
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[~hhlai1990], I have just checked the PR, it looks very promising.
I have a small doubt that I would like to share. Regarding "partial equi"
joins, we would have two possibilities:
- 1. Partial equi non-inner join: Enumerable(Hash)Join with remaining condition
- 2. Partial equi inner join: : Enumerable(Hash)Join (remaining condition null)
+ EnumerableFilter with remaining condition
For the sake of consistency and code simplicity, I wonder what is the advantage
of 2 vs 1 (if any), and if we should not remove option 2 and handle the inner
join case also using approach 1.
> Allow theta joins that have equi conditions to be executed using a hash join
> algorithm
> --------------------------------------------------------------------------------------
>
> Key: CALCITE-2973
> URL: https://issues.apache.org/jira/browse/CALCITE-2973
> Project: Calcite
> Issue Type: New Feature
> Components: core
> Affects Versions: 1.19.0
> Reporter: Lai Zhou
> Priority: Minor
> Labels: pull-request-available
> Fix For: 1.20.0
>
> Time Spent: 20m
> Remaining Estimate: 0h
>
> Now the EnumerableMergeJoinRule only supports an inner and equi join.
> If users make a theta-join query for a large dataset (such as 10000*10000),
> the nested-loop join process will take dozens of time than the sort-merge
> join process .
> So if we can apply merge-join or hash-join rule for a theta join, it will
> improve the performance greatly.
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