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https://issues.apache.org/jira/browse/HIVE-16869?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16045279#comment-16045279
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Yibing Shi commented on HIVE-16869:
-----------------------------------
The idea of the patch is to change the logic of predicate {{OR}}. Currently, if
a child of predicate {{OR}} returns a null predicate, this child is ignored.
This is not correct. A null predicate means that the condition is on a column
that doesn't exist in Parquet file (partition column etc.). In such a scenario,
the whole {{OR}} should be considered to true (returns null) so that the record
should be returned for further checking (if this {{OR}} is at top level) or the
parent predicate can be correctly evaluated (if current {{OR}} is a child of
another predicate).
> Hive returns wrong result when predicates on non-existing columns are pushed
> down to Parquet reader
> ---------------------------------------------------------------------------------------------------
>
> Key: HIVE-16869
> URL: https://issues.apache.org/jira/browse/HIVE-16869
> Project: Hive
> Issue Type: Bug
> Reporter: Yibing Shi
> Assignee: Yibing Shi
> Priority: Critical
> Attachments: HIVE-16869.1.patch, HIVE-16869.2.patch
>
>
> When {{hive.optimize.ppd}} and {{hive.optimize.index.filter}} are turned, and
> a select query has a condition on a column that doesn't exist in Parquet file
> (such as a partition column), Hive often returns wrong result.
> Please see below example for details:
> {noformat}
> hive> create table test_parq (a int, b int) partitioned by (p int) stored as
> parquet;
> OK
> Time taken: 0.292 seconds
> hive> insert overwrite table test_parq partition (p=1) values (1, 2);
> OK
> Time taken: 5.08 seconds
> hive> select * from test_parq where a=1 and p=1;
> OK
> 1 2 1
> Time taken: 0.441 seconds, Fetched: 1 row(s)
> hive> select * from test_parq where (a=1 and p=1) or (a=999 and p=999);
> OK
> 1 2 1
> Time taken: 0.197 seconds, Fetched: 1 row(s)
> hive> set hive.optimize.index.filter=true;
> hive> select * from test_parq where (a=1 and p=1) or (a=999 and p=999);
> OK
> Time taken: 0.167 seconds
> hive> select * from test_parq where (a=1 or a=999) and (a=999 or p=1);
> OK
> Time taken: 0.563 seconds
> {noformat}
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