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https://issues.apache.org/jira/browse/CALCITE-2979?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16840343#comment-16840343
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Danny Chan commented on CALCITE-2979:
-------------------------------------
It kind of have same thoughts as [~rubenql], let's make agreement that
Correlated variables are kind of "Columns" of the left table, but from this
design, it seems that the Correlated variables are multiple "Column" from left
table which comes to a component.
We actually could not expression such a logic from the plan.
> Add a block-based nested loop join algorithm
> --------------------------------------------
>
> Key: CALCITE-2979
> URL: https://issues.apache.org/jira/browse/CALCITE-2979
> Project: Calcite
> Issue Type: Improvement
> Components: core
> Affects Versions: 1.19.0
> Reporter: Stamatis Zampetakis
> Assignee: Khawla Mouhoubi
> Priority: Major
> Labels: performance
>
> Currently, Calcite provides a tuple-based nested loop join algorithm
> implemented through EnumerableCorrelate and EnumerableDefaults.correlateJoin.
> This means that for each tuple of the outer relation we probe (set variables)
> in the inner relation.
> The goal of this issue is to add new algorithm (or extend the correlateJoin
> method) which first gathers blocks (batches) of tuples from the outer
> relation and then probes the inner relation once per block.
> There are cases (eg., indexes) where the inner relation can be accessed by
> more than one value which can greatly improve the performance in particular
> when the outer relation is big.
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