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From "jean-claude (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (DRILL-4661) Optimze the LIKE function
Date Tue, 10 May 2016 10:50:13 GMT

     [ https://issues.apache.org/jira/browse/DRILL-4661?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

jean-claude updated DRILL-4661:
-------------------------------
    Fix Version/s: 1.7.0

> Optimze the LIKE function
> -------------------------
>
>                 Key: DRILL-4661
>                 URL: https://issues.apache.org/jira/browse/DRILL-4661
>             Project: Apache Drill
>          Issue Type: Improvement
>            Reporter: jean-claude
>            Priority: Minor
>             Fix For: 1.7.0
>
>
> The LIKE function is implemented using the java regex. This is different from the STRPOS
function which compares byte by byte.
> When doing to testing I've noticed that for cases where the user wants to do a restriction
like WHERE COL1 LIKE '%xyz%' it would be faster to actually do WHERE STRPOS(COL1, '%xyz%')
> 0
> I propose to change the LIKE operator's algorithm so that it detects if a byte by byte
compare could be applied and if so use the same technique as the STRPOS function. Cases of
the form '%xyz%', 'xyz%' and '%xyz' could be handled this way.



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