Riza Suminto has posted comments on this change. ( http://gerrit.cloudera.org:8080/21005 )
Change subject: IMPALA-12790: Fix overestimation in ScanNode.getInputCardinality ...................................................................... Patch Set 1: (1 comment) http://gerrit.cloudera.org:8080/#/c/21005/1/fe/src/main/java/org/apache/impala/util/MaxRowsProcessedVisitor.java File fe/src/main/java/org/apache/impala/util/MaxRowsProcessedVisitor.java: http://gerrit.cloudera.org:8080/#/c/21005/1/fe/src/main/java/org/apache/impala/util/MaxRowsProcessedVisitor.java@59 PS1, Line 59: // Stats is missing, so numRows might be a result of extrapolation that is > I am not 100% sure here - some clients may add a large limit for the sake o I agree, the HdfsScanNode seems pretty consistent in trying to always come up with reasonable inputCardinality_ value when stats is unavailable instead of just leaving it as -1. The same can not be said for KuduScanNode where it is possible to have inputCardnality = -1, such as in this test case: select * from kudu_planner_test.no_stats limit 1000; Before this patch, ScanNode.getInputCardinality() will return the LIMIT value and numRows will be equal to 1000. -- To view, visit http://gerrit.cloudera.org:8080/21005 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: Icc5b39a7684fb8748185349d0b80baf8dcd6b126 Gerrit-Change-Number: 21005 Gerrit-PatchSet: 1 Gerrit-Owner: Riza Suminto <[email protected]> Gerrit-Reviewer: Csaba Ringhofer <[email protected]> Gerrit-Reviewer: Impala Public Jenkins <[email protected]> Gerrit-Reviewer: Quanlong Huang <[email protected]> Gerrit-Reviewer: Riza Suminto <[email protected]> Gerrit-Comment-Date: Tue, 06 Feb 2024 17:34:11 +0000 Gerrit-HasComments: Yes
