Aman Sinha has posted comments on this change. ( http://gerrit.cloudera.org:8080/23924 )
Change subject: IMPALA-14102: [part 3] Modified LoptOptimizeJoinRule with Impala changes ...................................................................... Patch Set 6: (1 comment) http://gerrit.cloudera.org:8080/#/c/23924/6/java/calcite-planner/src/main/java/org/apache/impala/calcite/rules/ImpalaLoptOptimizeJoinRule.java File java/calcite-planner/src/main/java/org/apache/impala/calcite/rules/ImpalaLoptOptimizeJoinRule.java: http://gerrit.cloudera.org:8080/#/c/23924/6/java/calcite-planner/src/main/java/org/apache/impala/calcite/rules/ImpalaLoptOptimizeJoinRule.java@1930 PS6, Line 1930: public static boolean swapInputs(RelMetadataQuery mq, LoptMultiJoin multiJoin, One of the things that Impala's Planner.isInvertedJoinsCheaper() [1] considers is the parallelism (besides the cost). There are situations where if you only make the decision based on cost, the probe side can end up with much lower parallelism than without swapping and this adversely affects performance because the HashJoin node's parallelism depends on the left input's (probe) parallelism. Is the numNodes value available at this stage in the Calcite planning for the left and right child ? If so, it would be useful to incorporate. Whether in this patch or an enhancement. [1] https://github.com/apache/impala/blob/master/fe/src/main/java/org/apache/impala/planner/Planner.java#L826 -- To view, visit http://gerrit.cloudera.org:8080/23924 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I168ae903934c5c74520a22605e73f71dc0a9d549 Gerrit-Change-Number: 23924 Gerrit-PatchSet: 6 Gerrit-Owner: Steve Carlin <[email protected]> Gerrit-Reviewer: Aman Sinha <[email protected]> Gerrit-Reviewer: Fang-Yu Rao <[email protected]> Gerrit-Reviewer: Impala Public Jenkins <[email protected]> Gerrit-Reviewer: Joe McDonnell <[email protected]> Gerrit-Reviewer: Michael Smith <[email protected]> Gerrit-Reviewer: Steve Carlin <[email protected]> Gerrit-Comment-Date: Sat, 14 Feb 2026 20:31:57 +0000 Gerrit-HasComments: Yes
