[jira] [Commented] (DRILL-4905) Push down the LIMIT to the parquet reader scan to limit the numbers of records read

["ASF GitHub Bot (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/DRILL-4905?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15566419#comment-15566419 ] 

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

Github user ppadma commented on the issue:

    https://github.com/apache/drill/pull/597
  
    updated with new diffs. Please review.


> 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.
>  



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