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https://issues.apache.org/jira/browse/DRILL-4743?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15379768#comment-15379768
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ASF GitHub Bot commented on DRILL-4743:
---------------------------------------

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

    https://github.com/apache/drill/pull/534#discussion_r71012854
  
    --- Diff: 
exec/java-exec/src/main/java/org/apache/drill/exec/server/options/SystemOptionManager.java
 ---
    @@ -251,7 +254,12 @@ public void setOption(final OptionValue value) {
         final String name = value.name.toLowerCase();
         final OptionValidator validator = getValidator(name);
     
    -    validator.validate(value); // validate the option
    +    /* If the validator depends on other options */
    +    if (validator instanceof DependentTypeValidators) {
    +      ((DependentTypeValidators)validator).validate(value, this); // 
validate the option
    --- End diff --
    
    The validation is also done in the FallbackOptionManager. A testcase is 
present which checks the validation when changing the option in the session.


> HashJoin's not fully parallelized in query plan
> -----------------------------------------------
>
>                 Key: DRILL-4743
>                 URL: https://issues.apache.org/jira/browse/DRILL-4743
>             Project: Apache Drill
>          Issue Type: Bug
>    Affects Versions: 1.5.0
>            Reporter: Gautam Kumar Parai
>            Assignee: Gautam Kumar Parai
>              Labels: doc-impacting
>
> The underlying problem is filter selectivity under-estimate for a query with 
> complicated predicates e.g. deeply nested and/or predicates. This leads to 
> under parallelization of the major fragment doing the join. 
> To really resolve this problem we need table/column statistics to correctly 
> estimate the selectivity. However, in the absence of statistics OR even when 
> existing statistics are insufficient to get a correct estimate of selectivity 
> this will serve as a workaround.



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