hive-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Prasanth Jayachandran (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HIVE-12882) Automatically choose to use noscan for stats collection
Date Fri, 15 Jan 2016 22:37:40 GMT

    [ https://issues.apache.org/jira/browse/HIVE-12882?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15102603#comment-15102603
] 

Prasanth Jayachandran commented on HIVE-12882:
----------------------------------------------

RCFile still uses three modes with different semantics. noscan, partialscan and default full
scan. Dropping in the parser will break RCFile behaviour. As far as ORC is concerned, it really
doesn't matter what user specifies. 

> Automatically choose to use noscan for stats collection
> -------------------------------------------------------
>
>                 Key: HIVE-12882
>                 URL: https://issues.apache.org/jira/browse/HIVE-12882
>             Project: Hive
>          Issue Type: Sub-task
>            Reporter: Pengcheng Xiong
>
> noscan is leveraging the file system to derive the #rows and rawDataSize. According to
[~ashutoshc], it now only works with RC and ORC file type. We would like Hive to automatically
choose to use noscan or scan based on the file system when stats task starts or when user
issues the same query "Analyze ...."



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

Mime
View raw message