Bharath Vissapragada has posted comments on this change. ( http://gerrit.cloudera.org:8080/11901 )
Change subject: IMPALA-7528: Fix division by zero when computing cardinalities ...................................................................... Patch Set 1: (1 comment) http://gerrit.cloudera.org:8080/#/c/11901/1/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/11901/1/fe/src/main/java/org/apache/impala/planner/JoinNode.java@368 PS1, Line 368: if (lhsAdjNdv <= 0 && rhsAdjNdv <= 0) return 0; > Done. This is inline with ongoing changes for Tim qq, the actual cardinality (result) would still be 0 right? What is the advantage in overestimating if we know for sure it will be 0? Trying to understand. -- To view, visit http://gerrit.cloudera.org:8080/11901 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: Ieedd51d3ad6131a4ea2a5883f05104e6a0f2cd14 Gerrit-Change-Number: 11901 Gerrit-PatchSet: 1 Gerrit-Owner: Bikramjeet Vig <bikramjeet....@cloudera.com> Gerrit-Reviewer: Bharath Vissapragada <bhara...@cloudera.com> Gerrit-Reviewer: Bikramjeet Vig <bikramjeet....@cloudera.com> Gerrit-Reviewer: Impala Public Jenkins <impala-public-jenk...@cloudera.com> Gerrit-Reviewer: Tim Armstrong <tarmstr...@cloudera.com> Gerrit-Comment-Date: Wed, 07 Nov 2018 23:08:54 +0000 Gerrit-HasComments: Yes
