You are viewing a plain text version of this content. The canonical link for it is here.
Posted to issues@drill.apache.org by "ASF GitHub Bot (JIRA)" <ji...@apache.org> on 2016/04/02 05:44:25 UTC

[jira] [Commented] (DRILL-4573) Zero copy LIKE, REGEXP_MATCHES, SUBSTR

    [ https://issues.apache.org/jira/browse/DRILL-4573?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15222682#comment-15222682 ] 

ASF GitHub Bot commented on DRILL-4573:
---------------------------------------

GitHub user jcmcote opened a pull request:

    https://github.com/apache/drill/pull/458

    DRILL-4573: Zero copy LIKE, REGEXP_MATCHES, SUBSTR

    All the functions using the java.util.regex.Matcher are currently creating Java string objects to pass into the matcher.reset().
    However this creates unnecessary copy of the bytes and a Java string object.
    The matcher uses a CharSequence, so instead of making a copy we can create an adapter from the DrillBuffer to the CharSequence interface.
    Gains of 25% in execution speed are possible when going over VARCHAR of 36 chars. The gain will be proportional to the size of the VARCHAR.

You can merge this pull request into a Git repository by running:

    $ git pull https://github.com/jcmcote/drill DRILL-4573

Alternatively you can review and apply these changes as the patch at:

    https://github.com/apache/drill/pull/458.patch

To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:

    This closes #458
    
----
commit 71b35ecf5895fc8fbae1bf862cbb982787712ee2
Author: jean-claude cote <jc...@gmail.com>
Date:   2016-04-02T03:37:00Z

    DRILL-4573: Zero copy LIKE, REGEXP_MATCHES, SUBSTR

----


> Zero copy LIKE, REGEXP_MATCHES, SUBSTR
> --------------------------------------
>
>                 Key: DRILL-4573
>                 URL: https://issues.apache.org/jira/browse/DRILL-4573
>             Project: Apache Drill
>          Issue Type: Improvement
>            Reporter: jean-claude
>            Priority: Minor
>
> All the functions using the java.util.regex.Matcher are currently creating Java string objects to pass into the matcher.reset().
> However this creates unnecessary copy of the bytes and a Java string object.
> The matcher uses a CharSequence, so instead of making a copy we can create an adapter from the DrillBuffer to the CharSequence interface.
> Gains of 25% in execution speed are possible when going over VARCHAR of 36 chars. The gain will be proportional to the size of the VARCHAR.



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