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https://issues.apache.org/jira/browse/HIVE-11471?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14658959#comment-14658959
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Pengcheng Xiong commented on HIVE-11471:
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[~hagleitn], i am not sure, but I guess [~sershe] is asking the cost
(cardinality) of a query plan that is specified by the user. If that is the
case, i think the user can just turn off CBO and give Hive a query and run
explain, it will show the cost. For example, the plan that is given by CBO for
a query which joins A,B,C tables is A join B and then join C. The user can turn
off CBO and write the query like A join C join B, then run explain will show
the cost and the plan. The user can compare it with the plan that is given by
CBO.
> Expose query cost estimates (from CBO?) in explain plan
> -------------------------------------------------------
>
> Key: HIVE-11471
> URL: https://issues.apache.org/jira/browse/HIVE-11471
> Project: Hive
> Issue Type: Bug
> Reporter: Sergey Shelukhin
>
> Some users of Hive suggested that it would be useful to see abstract cost of
> the query plan in explain, so that different manual rewrites of the query
> could be compared before running.
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