[
https://issues.apache.org/jira/browse/HIVE-25335?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
zhengchenyu reassigned HIVE-25335:
----------------------------------
Assignee: zhengchenyu
> Unreasonable setting reduce number, when join big size table(but small row
> count) and small size table
> ------------------------------------------------------------------------------------------------------
>
> Key: HIVE-25335
> URL: https://issues.apache.org/jira/browse/HIVE-25335
> Project: Hive
> Issue Type: Improvement
> Reporter: zhengchenyu
> Assignee: zhengchenyu
> Priority: Major
>
> I found an application which is slow in our cluster, because the proccess
> bytes of one reduce is very huge, but only two reduce.
> when I debug, I found the reason. Because in this sql, one big size table
> (about 30G) with few row count(about 3.5M), another small size table (about
> 100M) have more row count (about 3.6M). So JoinStatsRule.process only use
> 100M to estimate reducer's number. But we need to process 30G byte in fact.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
