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https://issues.apache.org/jira/browse/HIVE-11405?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14648081#comment-14648081
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Prasanth Jayachandran commented on HIVE-11405:
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[~gopalv] is the column stats available for this query? If not your patch will
early terminate because of data size becoming 0 and AND evaluation terminating
early. Also I am not sure if this assumption is correct
{code}
final long branch2Rows = (newNumRows <= branchRows) ? 0 : (newNumRows -
branchRows);
{code}
I am still evaluating this change. The idea of mirroring the tree and passing
the branchRows to sibling branch looks good so far.
> Add early termination for recursion in
> StatsRulesProcFactory$FilterStatsRule.evaluateExpression for OR expression
> ------------------------------------------------------------------------------------------------------------------
>
> Key: HIVE-11405
> URL: https://issues.apache.org/jira/browse/HIVE-11405
> Project: Hive
> Issue Type: Bug
> Reporter: Hari Sankar Sivarama Subramaniyan
> Assignee: Prasanth Jayachandran
>
> Thanks to [~gopalv] for uncovering this issue as part of HIVE-11330. Quoting
> him,
> "The recursion protection works well with an AND expr, but it doesn't work
> against
> (OR a=1 (OR a=2 (OR a=3 (OR ...)
> since the for the rows will never be reduced during recursion due to the
> nature of the OR.
> We need to execute a short-circuit to satisfy the OR properly - no case which
> matches a=1 qualifies for the rest of the filters.
> Recursion should pass in the numRows - branch1Rows for the branch-2."
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