Riza Suminto has posted comments on this change. ( 
http://gerrit.cloudera.org:8080/20009 )

Change subject: IMPALA-12183: Fix cardinality clamping across aggregation phases
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Patch Set 5:

(1 comment)

http://gerrit.cloudera.org:8080/#/c/20009/5/testdata/workloads/functional-planner/queries/PlannerTest/tpcds/tpcds-q67.test
File 
testdata/workloads/functional-planner/queries/PlannerTest/tpcds/tpcds-q67.test:

http://gerrit.cloudera.org:8080/#/c/20009/5/testdata/workloads/functional-planner/queries/PlannerTest/tpcds/tpcds-q67.test@512
PS5, Line 512: mem
> This is a significant reduction in memory estimate. Is this because the car
This is because prior to this patch, each agg class is capped with 
inputCardinality = getChild(0).getCardinality();
In this case, inputCardinality = 15.09M, which is all rows coming out of 
16:EXCHANGE.

But according to my discussion with Aman, since this is FIRST_MERGE agg, not 
all 15.09M goes through all 9 agg classes.
Instead, each agg stream will pass to their own agg class. For example, only 1 
row will pass to Class 8 here, and the rest of (15.09M - 1) rows distributed to 
other 8 agg classes separately.



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Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-MessageType: comment
Gerrit-Change-Id: I1d414fe56b027f887c7f901d8a6799a388b16b95
Gerrit-Change-Number: 20009
Gerrit-PatchSet: 5
Gerrit-Owner: Riza Suminto <[email protected]>
Gerrit-Reviewer: Abhishek Rawat <[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: Fri, 09 Jun 2023 23:57:58 +0000
Gerrit-HasComments: Yes

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