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https://issues.apache.org/jira/browse/HIVE-7215?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14028750#comment-14028750
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Prasanth J commented on HIVE-7215:
----------------------------------

ORC handles nulls in predicate pushdown. If an entire column is null in a row 
group (10K rows), the statistics in row index entries is null. So for queries 
like {code}select * from table where col is null {code} if col is completely 
null in a row group, ORC predicate pushdown evaluates to true (based on null 
statistics) and reads the row group.

> Support predicate pushdown for null checks in ORCFile
> -----------------------------------------------------
>
>                 Key: HIVE-7215
>                 URL: https://issues.apache.org/jira/browse/HIVE-7215
>             Project: Hive
>          Issue Type: Improvement
>            Reporter: Rohini Palaniswamy
>
> Came across this missing feature during discussion of PIG-3760.



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