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From "Sean Owen (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (SPARK-19655) select count(*) , requests 1 for each row
Date Sat, 18 Feb 2017 10:13:44 GMT

    [ https://issues.apache.org/jira/browse/SPARK-19655?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15873087#comment-15873087
] 

Sean Owen commented on SPARK-19655:
-----------------------------------

What is the problem? selecting "1" _is_ an optimization, or at least, should make no difference
at all.

> select count(*) , requests 1 for each row
> -----------------------------------------
>
>                 Key: SPARK-19655
>                 URL: https://issues.apache.org/jira/browse/SPARK-19655
>             Project: Spark
>          Issue Type: Bug
>          Components: SQL
>    Affects Versions: 2.1.0
>            Reporter: hosein
>            Priority: Minor
>
> when I want query select count( * ) by JDBC and monitor queries in database side, I see
spark requests: select 1 for destination table
> it means 1 for each row and it is not optimized



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