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https://issues.apache.org/jira/browse/IMPALA-15710?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Peter Rozsa resolved IMPALA-15710.
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Fix Version/s: Impala 5.1.0
Resolution: Fixed
> Improve cardinality estimates of deletes in Hive ACID tables
> ------------------------------------------------------------
>
> Key: IMPALA-15710
> URL: https://issues.apache.org/jira/browse/IMPALA-15710
> Project: IMPALA
> Issue Type: Improvement
> Components: Frontend
> Reporter: Csaba Ringhofer
> Assignee: Csaba Ringhofer
> Priority: Major
> Fix For: Impala 5.1.0
>
>
> Currently the estimated number of deleted rows is calculated based on the
> number of rows in the whole table, which can massively overestimate the real
> number and lead to inflated mem estimates for the anti-join operator that
> adds the delete. I don't know of precise stats available for this, but
> calculating some cap based on the size of delete files could reduce extreme
> overestimation.
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