Aman Sinha has posted comments on this change. ( 
http://gerrit.cloudera.org:8080/20194 )

Change subject: IMPALA-12282: Refine correlation factor in AggregationNode
......................................................................


Patch Set 1:

(1 comment)

http://gerrit.cloudera.org:8080/#/c/20194/1/fe/src/main/java/org/apache/impala/planner/AggregationNode.java
File fe/src/main/java/org/apache/impala/planner/AggregationNode.java:

http://gerrit.cloudera.org:8080/#/c/20194/1/fe/src/main/java/org/apache/impala/planner/AggregationNode.java@687
PS1, Line 687:             
Math.pow(queryOptions.getAgg_mem_correlation_factor(), nonLiteralExprCount);
I missed one detail when reviewing the previous patch (IMPALA-11842) .. the 
exponent should be N-1 rather than N since the correlation factor is 
representing correlation between 2 columns.  If N = 2 and correlation_factor = 
0.2, we should multiply once by 0.2.  If N.= 1, there shouldn't be a need to 
multiply by the correlation factor. What do you think ?



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Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-MessageType: comment
Gerrit-Change-Id: I4ffa9e82b83e7c0042bd918ac132668a47505688
Gerrit-Change-Number: 20194
Gerrit-PatchSet: 1
Gerrit-Owner: Riza Suminto <[email protected]>
Gerrit-Reviewer: Aman Sinha <[email protected]>
Gerrit-Reviewer: Impala Public Jenkins <[email protected]>
Gerrit-Reviewer: Kurt Deschler <[email protected]>
Gerrit-Reviewer: Riza Suminto <[email protected]>
Gerrit-Comment-Date: Thu, 13 Jul 2023 23:10:21 +0000
Gerrit-HasComments: Yes

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