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Jinfeng Ni commented on DRILL-4573: ----------------------------------- If there is no faster way, I think 7% overhead is the necessary cost Drill has to pay to get things correct, without forcing user to tell Drill whether the input is ASCII only or not. Even with this 7% overhead, it still shows 17% improvement, which is good thing. Can you please wrap what you have so far, and submit a new pull request or patch? > 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: Critical > Fix For: 1.7.0 > > Attachments: DRILL-4573-3.patch.txt, 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)