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https://issues.apache.org/jira/browse/DERBY-6938?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16110605#comment-16110605
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Harshvardhan Gupta commented on DERBY-6938:
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Bryan,
I agree with your observations. For production of efficient query plans,
Cardinality Estimates, Cost estimation and Plan space are all inter dependent
on each other. I am filing another issue under DERBY-6949 to track the effort
on modelling HASH join's spill behaviour. I will also update cost modelling
details under DERBY-6949 shortly after I had to take a detour analyzing HASH
Join's behaviour.
Thanks,
Vardhan
> 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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