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ASF GitHub Bot commented on DRILL-4573: --------------------------------------- Github user jcmcote commented on the pull request: https://github.com/apache/drill/pull/458#issuecomment-208043910 I have updated the JIRA ticket with the latest patch. Using this approach you can expect 25% less time to execute the like UDF. I've added details in the JIRA ticket. All tests pass. > 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. -- This message was sent by Atlassian JIRA (v6.3.4#6332)