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Posted to dev@hive.apache.org by "Prasanth Jayachandran (JIRA)" <ji...@apache.org> on 2014/12/18 23:12:13 UTC

[jira] [Created] (HIVE-9166) Place an upper bound for SARG CNF conversion

Prasanth Jayachandran created HIVE-9166:
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             Summary: Place an upper bound for SARG CNF conversion
                 Key: HIVE-9166
                 URL: https://issues.apache.org/jira/browse/HIVE-9166
             Project: Hive
          Issue Type: Bug
    Affects Versions: 0.14.0, 0.15.0
            Reporter: Prasanth Jayachandran
            Assignee: Prasanth Jayachandran


SARG creation in ORC, applies several optimizations to expression tree. In that CNF conversion is an exponential algorithm as it finds all combinations of expressions when converting from OR of AND form to AND of OR form (CNF). We need an upper bound for this algorithm to prevent it from running for long time and generating huge combinations list.



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