[jira] [Assigned] (HIVE-27138) MapJoinOperator throws NPE when computing OuterJoin with filter expressions on small table

["Seonggon Namgung (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HIVE-27138?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Seonggon Namgung reassigned HIVE-27138:
---------------------------------------


> MapJoinOperator throws NPE when computing OuterJoin with filter expressions on small table
> ------------------------------------------------------------------------------------------
>
>                 Key: HIVE-27138
>                 URL: https://issues.apache.org/jira/browse/HIVE-27138
>             Project: Hive
>          Issue Type: Bug
>            Reporter: Seonggon Namgung
>            Assignee: Seonggon Namgung
>            Priority: Major
>
> Hive throws NPE when running mapjoin_filter_on_outerjoin.q using Tez engine. (I used TestMiniLlapCliDriver.)
> The NPE is thrown by CommonJoinOperator.getFilterTag(), which just retreives the last object from the given list.
> To the best of my knowledge, if Hive selects MapJoin to perform Join operation, filterTag should be computed and appended to a row before the row is passed to MapJoinOperator.
> In the case of MapReduce engine, this is done by HashTableSinkOperator.
> However, I cannot find any logic pareparing filterTag for small tables when Hive uses Tez engine.
> I think there are 2 available options:
> 1. Don't use MapJoinOperator if a small table has filter expression.
> 2. Add a new logic that computes and passes filterTag to MapJoinOperator.
> I am working on the second option and ready to discuss about it.
> It would be grateful if you could give any opinion about this issue.



--
This message was sent by Atlassian Jira
(v8.20.10#820010)