Kurt Deschler 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: (1 comment) http://gerrit.cloudera.org:8080/#/c/19682/6/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/19682/6/fe/src/main/java/org/apache/impala/planner/JoinNode.java@500 PS6, Line 500: result = (long) Math.min(result, ((cumulative_sel * lhsCard) * rhsCard)/corrfactor); > This would be more readable as (lhsCard * rhsCard)* cumulative_sel / corrfa NM I see now the multiply here is to convert back to cardinality. Guessing that selectivity factor was only introduced to avoid large multiplies but double probably could have handled that. -- To view, visit http://gerrit.cloudera.org:8080/19682 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings 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: Tue, 11 Apr 2023 14:57:59 +0000 Gerrit-HasComments: Yes
