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Posted to dev@hive.apache.org by "Prasanth Jayachandran (JIRA)" <ji...@apache.org> on 2014/12/18 23:13:14 UTC

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

     [ https://issues.apache.org/jira/browse/HIVE-9166?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Prasanth Jayachandran updated HIVE-9166:
----------------------------------------
    Attachment: HIVE-9166.1.patch

> 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
>              Labels: orcfile
>         Attachments: HIVE-9166.1.patch
>
>
> 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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