[ 
https://issues.apache.org/jira/browse/DRILL-2723?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Jacques Nadeau updated DRILL-2723:
----------------------------------
    Fix Version/s:     (was: 1.0.0)
                   1.2.0

> Inaccurate row count estimate for text files results in BroadcastExchange
> -------------------------------------------------------------------------
>
>                 Key: DRILL-2723
>                 URL: https://issues.apache.org/jira/browse/DRILL-2723
>             Project: Apache Drill
>          Issue Type: Bug
>          Components: Query Planning & Optimization
>            Reporter: Steven Phillips
>            Assignee: Jacques Nadeau
>             Fix For: 1.2.0
>
>
> The current method for estimating row count in text files is to divide the 
> size of the file in bytes by 1024. This row count estimate is used by 
> optimizer to decide if BroadcastExchange should be used.
> This results in massive memory consumption when using BroadCast exchange on a 
> large table.
> We need a better way of estimating row count, or use a different metric when 
> deciding to use BroadcastExchange.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Reply via email to