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https://issues.apache.org/jira/browse/DRILL-4573?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15255031#comment-15255031
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ASF GitHub Bot commented on DRILL-4573:
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Github user jcmcote commented on the pull request:
https://github.com/apache/drill/pull/458#issuecomment-213647876
I guess it slipped through the cracks. No worries.
I did not convert the "isnumeric" UDF to use a CharSequence wrapper since I
don't really understand how the templating mechanism works. How difficult would
it be to change isnumeric to use a wrapper?
> 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
> Attachments: DRILL-4573.patch.txt
>
>
> 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.
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