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Posted to issues-all@impala.apache.org by "Shant Hovsepian (Jira)" <ji...@apache.org> on 2020/09/23 04:48:00 UTC

[jira] [Created] (IMPALA-10185) Leverage boolean statistics for computing selectivity

Shant Hovsepian created IMPALA-10185:
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             Summary: Leverage boolean statistics for computing selectivity
                 Key: IMPALA-10185
                 URL: https://issues.apache.org/jira/browse/IMPALA-10185
             Project: IMPALA
          Issue Type: Improvement
    Affects Versions: Impala 3.4.0
            Reporter: Shant Hovsepian
            Assignee: Shant Hovsepian


As part of computing stats for a boolean column we record the value counts.

numTrues, numFalses, numNulls.

However when calculating cardinality for boolean column predicates the selectivity of 1/3 is always used instead of factoring the value distribution recorded in the stats.



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