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 3: (2 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@330 PS1, Line 330: return getGenericJoinCardinality(eqJoinConjunctSlots, otherEqJoinStats, lhsCard, > line too long (95 > 90) Done http://gerrit.cloudera.org:8080/#/c/19682/1/fe/src/main/java/org/apache/impala/planner/JoinNode.java@421 PS1, Line 421: if (analyzer.getQueryOptions().isUse_multiplied_selectivity_for_join()) { > +1 for making this more flexible Thanks for the suggestion. So conceptually a coefficient which is less than 1.0 (and > 0) would mean that the combined selectivity: (sel1 x sel2 x 1/coefficient) is *higher* than what the current formula that does the multiplication of selectivity would compute. I doubt we will need to go in the other direction, i.e lower than the product of the selectivities. Let me modify this query option. -- 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: 3 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: Thu, 06 Apr 2023 00:58:29 +0000 Gerrit-HasComments: Yes
