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ASF GitHub Bot commented on DRILL-5697: --------------------------------------- Github user paul-rogers commented on a diff in the pull request: https://github.com/apache/drill/pull/907#discussion_r134035974 --- Diff: exec/java-exec/src/test/java/org/apache/drill/exec/expr/fn/impl/TestStringFunctions.java --- @@ -157,6 +157,967 @@ public void testRegexpReplace() throws Exception { } @Test + public void testLikeStartsWith() throws Exception { + + // all ASCII. + testBuilder() --- End diff -- The regex parsing and execution code is becoming complex. Let's test it with a true unit test, not just a system-level test using a query. See the test frameworks available. We can also discuss in person. > Improve performance of filter operator for pattern matching > ----------------------------------------------------------- > > Key: DRILL-5697 > URL: https://issues.apache.org/jira/browse/DRILL-5697 > Project: Apache Drill > Issue Type: Improvement > Components: Execution - Flow > Affects Versions: 1.11.0 > Reporter: Padma Penumarthy > Assignee: Padma Penumarthy > > Queries using filter with sql like operator use Java regex library for > pattern matching. However, for cases like %abc (ends with abc), abc% (starts > with abc), %abc% (contains abc), it is observed that implementing these cases > with simple code instead of using regex library provides good performance > boost (4-6x). Idea is to use special case code for simple, common cases and > fall back to Java regex library for complicated ones. That will provide good > performance benefit for most common cases. -- This message was sent by Atlassian JIRA (v6.4.14#64029)