Michael Smith has posted comments on this change. ( 
http://gerrit.cloudera.org:8080/21687 )

Change subject: IMPALA-5443: Apply codegen rows threshold per node
......................................................................


Patch Set 3:

(1 comment)

http://gerrit.cloudera.org:8080/#/c/21687/2/fe/src/main/java/org/apache/impala/util/PlanNodeCodegenVisitor.java
File fe/src/main/java/org/apache/impala/util/PlanNodeCodegenVisitor.java:

http://gerrit.cloudera.org:8080/#/c/21687/2/fe/src/main/java/org/apache/impala/util/PlanNodeCodegenVisitor.java@57
PS2, Line 57:     long numRowsPerInstance = (long)Math.ceil(numRows / 
(double)numNodes);
I think it would make sense for this visitor to take into account 
ProcessingCost or expression complexity. An simple expression that's trivial to 
codegen seems like it would be worth doing for fewer rows than a really complex 
expression that takes awhile to codegen. Although presumably the interpreted 
cost also goes up. Need to come up with a methodology for deciding the 
threshold and how query characteristics affect it.



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Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-MessageType: comment
Gerrit-Change-Id: I1b34d4f2ef0d98fcd918a8a546acde70e09d18d7
Gerrit-Change-Number: 21687
Gerrit-PatchSet: 3
Gerrit-Owner: Michael Smith <[email protected]>
Gerrit-Reviewer: Impala Public Jenkins <[email protected]>
Gerrit-Reviewer: Michael Smith <[email protected]>
Gerrit-Comment-Date: Wed, 21 Aug 2024 00:36:40 +0000
Gerrit-HasComments: Yes

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