Aman Sinha has posted comments on this change. ( 
http://gerrit.cloudera.org:8080/19682 )

Change subject: IMPALA-12006: Improve cardinality estimation for joins 
involving multiple conjuncts
......................................................................


Patch Set 6:

(5 comments)

http://gerrit.cloudera.org:8080/#/c/19682/1/fe/src/main/java/org/apache/impala/planner/JoinNode.java
File fe/src/main/java/org/apache/impala/planner/JoinNode.java:

http://gerrit.cloudera.org:8080/#/c/19682/1/fe/src/main/java/org/apache/impala/planner/JoinNode.java@421
PS1, Line 421:           slots.lhsNumRows(), slots.rhsNumRows(), lhsCard, 
rhsCard));
> Correct, the result will be somewhere between the multiplied selectivity an
Done


http://gerrit.cloudera.org:8080/#/c/19682/3/fe/src/main/java/org/apache/impala/planner/JoinNode.java
File fe/src/main/java/org/apache/impala/planner/JoinNode.java:

http://gerrit.cloudera.org:8080/#/c/19682/3/fe/src/main/java/org/apache/impala/planner/JoinNode.java@414
PS3, Line 414: kState(!eqJoinC
> Hitting the limit seems possible here with big RHS+LHS and could lead to we
Ack.  Changed it to divide by the lhsCard, rhsCard.


http://gerrit.cloudera.org:8080/#/c/19682/3/fe/src/main/java/org/apache/impala/planner/JoinNode.java@434
PS3, Line 434:
> This seems to be the same logic as in the loop above. I think that it would
Refactored this.


http://gerrit.cloudera.org:8080/#/c/19682/3/fe/src/main/java/org/apache/impala/planner/JoinNode.java@443
PS3, Line 443:     if (corrfactor > 0) {
> This could be moved to line 430.
I think we still need to check the final result is >=0 since result is getting 
modified at a couple of places.


http://gerrit.cloudera.org:8080/#/c/19682/3/fe/src/main/java/org/apache/impala/planner/JoinNode.java@487
PS3, Line 487:     double cumulative_sel = 1.0;
> Should we consider multiply the selectivity here too? (if the query option
Yes, thanks for pointing this.  Added the same logic here.



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Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-MessageType: comment
Gerrit-Change-Id: I845d778a58404af834f7501fc8157a5a4b4bcc35
Gerrit-Change-Number: 19682
Gerrit-PatchSet: 6
Gerrit-Owner: Aman Sinha <[email protected]>
Gerrit-Reviewer: Aman Sinha <[email protected]>
Gerrit-Reviewer: Csaba Ringhofer <[email protected]>
Gerrit-Reviewer: Impala Public Jenkins <[email protected]>
Gerrit-Reviewer: Kurt Deschler <[email protected]>
Gerrit-Reviewer: Quanlong Huang <[email protected]>
Gerrit-Comment-Date: Sun, 09 Apr 2023 06:25:58 +0000
Gerrit-HasComments: Yes

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