Quanlong Huang has posted comments on this change. ( http://gerrit.cloudera.org:8080/24556 )
Change subject: IMPALA-15127: Support HBO for UnionNode cardinality ...................................................................... Patch Set 8: (1 comment) http://gerrit.cloudera.org:8080/#/c/24556/8/fe/src/main/java/org/apache/impala/planner/UnionNode.java File fe/src/main/java/org/apache/impala/planner/UnionNode.java: http://gerrit.cloudera.org:8080/#/c/24556/8/fe/src/main/java/org/apache/impala/planner/UnionNode.java@376 PS8, Line 376: sb.append("constOps:").append(constExprLists_.size()).append("|"); > So we're just counting the constant operations and not showing what's in th That's a good point! I think conjuncts might be safe since they will be migrated into the UnionStmt: https://github.com/apache/impala/blob/c7dd8b5f95e262065a682e5cbf80645f3bc2809a/fe/src/main/java/org/apache/impala/planner/SingleNodePlanner.java#L2353-L2355 Const operands that don't survive in the predicates will be marked as hasEmptyResultSet=true then be skipped: https://github.com/apache/impala/blob/c7dd8b5f95e262065a682e5cbf80645f3bc2809a/fe/src/main/java/org/apache/impala/planner/SingleNodePlanner.java#L2297-L2308 Then at the point of creating UnionNode, the const operands are all valid. However, if downstream PlanNodes aggregate or join on the const operand results, the cardinality might change. I think the ancestor nodes can pass down this info when generating HBO key strings of their children. Such use case seems rare so let's fix it in a future patch. -- To view, visit http://gerrit.cloudera.org:8080/24556 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: Ie228f530bdcb171d3b717966673164bf9a4c45c8 Gerrit-Change-Number: 24556 Gerrit-PatchSet: 8 Gerrit-Owner: Quanlong Huang <[email protected]> Gerrit-Reviewer: Aman Sinha <[email protected]> Gerrit-Reviewer: Impala Public Jenkins <[email protected]> Gerrit-Reviewer: Quanlong Huang <[email protected]> Gerrit-Reviewer: Steve Carlin <[email protected]> Gerrit-Comment-Date: Fri, 31 Jul 2026 08:52:24 +0000 Gerrit-HasComments: Yes
