[jira] [Commented] (HIVE-22538) RS deduplication does not always enforce hive.optimize.reducededuplication.min.reducer

["Peter Vary (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/HIVE-22538?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16988815#comment-16988815 ] 

Peter Vary commented on HIVE-22538:
-----------------------------------

[~jcamachorodriguez]: Any news here?

> RS deduplication does not always enforce hive.optimize.reducededuplication.min.reducer
> --------------------------------------------------------------------------------------
>
>                 Key: HIVE-22538
>                 URL: https://issues.apache.org/jira/browse/HIVE-22538
>             Project: Hive
>          Issue Type: Bug
>          Components: Physical Optimizer
>            Reporter: Jesus Camacho Rodriguez
>            Assignee: Jesus Camacho Rodriguez
>            Priority: Major
>              Labels: pull-request-available
>         Attachments: HIVE-22538.patch
>
>          Time Spent: 10m
>  Remaining Estimate: 0h
>
> For transactional tables, that property might be overriden to 1, which can lead to merging final aggregation into a single stage (hence leading to performance degradation). For instance, when autogather column stats is enabled, this can happen for the following query:
> {code}
> set hive.support.concurrency=true;
> set hive.txn.manager=org.apache.hadoop.hive.ql.lockmgr.DbTxnManager;
> EXPLAIN
> CREATE TABLE x STORED AS ORC TBLPROPERTIES('transactional'='true') AS
> SELECT * FROM SRC x CLUSTER BY x.key;
> {code}



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