[
https://issues.apache.org/jira/browse/SPARK-19655?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15873102#comment-15873102
]
Sean Owen commented on SPARK-19655:
-----------------------------------
There are queries issued to test the existence of tables in some dialects, but
they issue "SELECT 1 ... LIMIT 1".
There isn't Vertica support in Spark. Is this query possibly coming from a
third-party library?
> 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
--
This message was sent by Atlassian JIRA
(v6.3.15#6346)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
