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https://issues.apache.org/jira/browse/HIVE-21915?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Wei Zhang updated HIVE-21915:
-----------------------------
    Labels: patch  (was: pull-request-available)

> Hive with TEZ UNION ALL and UDTF results in data loss
> -----------------------------------------------------
>
>                 Key: HIVE-21915
>                 URL: https://issues.apache.org/jira/browse/HIVE-21915
>             Project: Hive
>          Issue Type: Bug
>    Affects Versions: 1.2.1
>            Reporter: Wei Zhang
>            Assignee: Wei Zhang
>            Priority: Major
>              Labels: patch
>         Attachments: hive-21915-2019-06-24.patch
>
>
> The HQL syntax is like this:
> CREATE TEMPORARY TABLE tez_union_all_loss_data AS
> SELECT xxx, yyy, zzz,1 as tag
> FROM ods_1
> UNION ALL
> SELECT xxx, yyy, zzz, tag
> FROM
> (
> SELECT xxx
> ,get_json_object(get_json_object(tb,'$.a'),'$.b') AS yyy
> ,zzz
> ,2 as tag
> FROM ods_2
> LATERAL VIEW EXPLODE(some_udf(uuu)) team_number AS tb
> ) tbl 
> ;
>  
> With above HQL, we are expecting that rows with both tag = 2 and tag = 1 
> appear. In our case however, all the rows with tag = 1 are lost.
> Dig deeper we can find that the generated two maps have identical task tmp 
> paths. And that results from when UDTF is present, the FileSinkOperator will 
> be processed twice generating the tmp path in 
> GenTezUtils.removeUnionOperators();
>  



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