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https://issues.apache.org/jira/browse/DERBY-6938?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16097272#comment-16097272
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Harshvardhan Gupta commented on DERBY-6938:
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Summarizing my analysis of HASH based joins so far -
Derby has the capability to perform HASH Joins spilling to disk but has long
ignored them due to the absence of a cost model around such a behaviour.
DERBY-1259 also talks about the history of HASH Joins and the changes made as
part of DERBY-106.
> Obtain cardinality estimates and true estimates for base tables as well as
> for intermediate results for queries involving multiple joins.
> -------------------------------------------------------------------------------------------------------------------------------------------
>
> Key: DERBY-6938
> URL: https://issues.apache.org/jira/browse/DERBY-6938
> Project: Derby
> Issue Type: Sub-task
> Components: SQL
> Reporter: Harshvardhan Gupta
> Assignee: Harshvardhan Gupta
> Attachments: explain.txt, traceout.txt
>
>
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