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https://issues.apache.org/jira/browse/IMPALA-14324?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Steve Carlin resolved IMPALA-14324.
-----------------------------------
Assignee: Steve Carlin
Resolution: Fixed
> Calcite planner: Wrong cardinality shown with is_not_null predicate in scan
> node
> --------------------------------------------------------------------------------
>
> Key: IMPALA-14324
> URL: https://issues.apache.org/jira/browse/IMPALA-14324
> Project: IMPALA
> Issue Type: Sub-task
> Reporter: Steve Carlin
> Assignee: Steve Carlin
> Priority: Major
>
> Taken from review: [https://gerrit.cloudera.org/#/c/22870]
> When running TpcdsCpuCostPlannerTest under the java/calcite-planner
> directory, the cardinality for store_returns is showing up as: (filtered from
> 86.40M)
> It should be 864M. The reason it is only .1 times the size is because the
> is_not_null pred filter selectivity is being treated as filtering out 90% of
> the rows. This is due to the Planner::computeSelectivities method using the
> following lines:
> {code:java}
> if (selectivities.size() != conjunctSize) {
> // Some conjuncts have no estimated selectivity. Use a single default
> // representative selectivity for all those conjuncts.
> selectivities.add(Expr.DEFAULT_SELECTIVITY);
> }{code}
> We need the getSelectivity for the "is not null" predicate expression to
> return the right result.
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