drill-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "ASF GitHub Bot (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (DRILL-4905) Push down the LIMIT to the parquet reader scan to limit the numbers of records read
Date Fri, 21 Oct 2016 21:16:58 GMT

    [ https://issues.apache.org/jira/browse/DRILL-4905?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15596393#comment-15596393
] 

ASF GitHub Bot commented on DRILL-4905:
---------------------------------------

Github user jinfengni commented on the issue:

    https://github.com/apache/drill/pull/597
  
    +1
    
    Thanks for the PR. It's good that you added couple of more unit tests. 



> Push down the LIMIT to the parquet reader scan to limit the numbers of records read
> -----------------------------------------------------------------------------------
>
>                 Key: DRILL-4905
>                 URL: https://issues.apache.org/jira/browse/DRILL-4905
>             Project: Apache Drill
>          Issue Type: Bug
>          Components: Storage - Parquet
>    Affects Versions: 1.8.0
>            Reporter: Padma Penumarthy
>            Assignee: Padma Penumarthy
>             Fix For: 1.9.0
>
>
> Limit the number of records read from disk by pushing down the limit to parquet reader.
> For queries like
> select * from <table> limit N; 
> where N < size of Parquet row group, we are reading 32K/64k rows or entire row group.
This needs to be optimized to read only N rows.
>  



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

Mime
View raw message