Aleksandr Efimov has posted comments on this change. ( http://gerrit.cloudera.org:8080/24718 )
Change subject: IMPALA-15278: Fix incorrect cardinality with OFFSET ...................................................................... Patch Set 3: (2 comments) http://gerrit.cloudera.org:8080/#/c/24718/3/fe/src/main/java/org/apache/impala/planner/PlanNode.java File fe/src/main/java/org/apache/impala/planner/PlanNode.java: http://gerrit.cloudera.org:8080/#/c/24718/3/fe/src/main/java/org/apache/impala/planner/PlanNode.java@816 PS3, Line 816: protected long capCardinalityAtLimit(long cardinality, long offset) { > That makes sense. applySelectivity() also does this for IMPALA-8647. Checked it out: subquery-rewrite.test is gone from the patch, so the NESTED LOOP JOIN keeps its RIGHT SEMI shape and the inputs no longer swap. The wording matches applySelectivity() at line 939 too, so the two places now read the same. Looks settled. http://gerrit.cloudera.org:8080/#/c/24718/3/testdata/workloads/functional-planner/queries/PlannerTest/card-limit-offset.test File testdata/workloads/functional-planner/queries/PlannerTest/card-limit-offset.test: http://gerrit.cloudera.org:8080/#/c/24718/3/testdata/workloads/functional-planner/queries/PlannerTest/card-limit-offset.test@16 PS3, Line 16: # OFFSET in MERGING-EXCHANGE > Added such tests. The two new sections cover it. I recomputed the numbers against the new formula rather than reading them off: 730 - 6200 clamps to 1 in the TOP-N, and in the distributed shape the local TOP-N stays at 730 while the merging exchange clamps to 1. Both match the goldens. -- To view, visit http://gerrit.cloudera.org:8080/24718 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I3b628beabc5c7ec6c4fdda9dff6aaf7a4acae538 Gerrit-Change-Number: 24718 Gerrit-PatchSet: 3 Gerrit-Owner: Quanlong Huang <[email protected]> Gerrit-Reviewer: Aleksandr Efimov <[email protected]> Gerrit-Reviewer: Impala Public Jenkins <[email protected]> Gerrit-Reviewer: Michael Smith <[email protected]> Gerrit-Reviewer: Quanlong Huang <[email protected]> Gerrit-Comment-Date: Tue, 01 Sep 2026 06:32:56 +0000 Gerrit-HasComments: Yes
