[jira] [Commented] (TRAFODION-2404) enhance REGEXP performance

[ASF GitHub Bot (JIRA)]

    [ 
https://issues.apache.org/jira/browse/TRAFODION-2404?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16586581#comment-16586581
 ] 

ASF GitHub Bot commented on TRAFODION-2404:
-------------------------------------------

Github user DaveBirdsall commented on a diff in the pull request:

    https://github.com/apache/trafodion/pull/1699#discussion_r211423746
  
    --- Diff: core/sql/exp/exp_like.cpp ---
    @@ -513,11 +512,16 @@ ex_expr::exp_return_type 
ExRegexpClauseChar::eval(char *op_data[],
     
       str_cpy_all(pattern, op_data[2], len2);
       str_cpy_all(srcStr, op_data[1], len1);
    -
    -  z = regcomp(&reg, pattern, cflags);
    +  if(rpattern_ != pattern)
    --- End diff --
    
    This is a pointer comparison rather than a content comparison. Since 
rpattern_ is a data member and pattern is a stack variable, I expect this 
comparison will always mismatch, so (rpattern_ != pattern) will always be true. 
I am guessing that you intended to compare the content instead?


> enhance REGEXP performance
> --------------------------
>
>                 Key: TRAFODION-2404
>                 URL: https://issues.apache.org/jira/browse/TRAFODION-2404
>             Project: Apache Trafodion
>          Issue Type: Improvement
>            Reporter: liu ming
>            Assignee: liu ming
>            Priority: Major
>
> There are rooms to enhance the performance of REGEXP from code review 
> comments by Dave Birdsall. More details will be added.



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)