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https://issues.apache.org/jira/browse/PHOENIX-2198?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14730254#comment-14730254
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Maryann Xue commented on PHOENIX-2198:
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bq. Is it not currently possible to use the CorrelatedPlan in Phoenix, but only
from the Calcite branch?
Correct. In most cases, nested-loop join would have the worse performance,
unless we know in advance (from stats) that the outer relation is only going to
produce a very limited number of rows and executing the inner relation is cheap
(for example a point lookup). So I think this would only be worthwhile in
Phoenix + Calcite, where we can cost it. CorrelatedPlan is also used where
correlated subqueries that cannot be de-correlated (not very common though),
and Phoenix does not have this front-end support yet.
> Support correlate variable
> --------------------------
>
> Key: PHOENIX-2198
> URL: https://issues.apache.org/jira/browse/PHOENIX-2198
> Project: Phoenix
> Issue Type: New Feature
> Reporter: Maryann Xue
> Assignee: Maryann Xue
> Attachments: PHOENIX-2198.patch
>
> Original Estimate: 240h
> Remaining Estimate: 240h
>
> This will enable the outer query to set a correlate variable as a parameter
> to restart the inner query for each iteration.
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