Tim Armstrong has posted comments on this change. ( http://gerrit.cloudera.org:8080/16880 )
Change subject: IMPALA-9687 Improve estimates for number of hosts in Kudu plans ...................................................................... Patch Set 2: (2 comments) This is a good improvement, thank you! I had a couple more requested tweaks then I think this will be in a good state to be merged. http://gerrit.cloudera.org:8080/#/c/16880/2/fe/src/main/java/org/apache/impala/planner/KuduScanNode.java File fe/src/main/java/org/apache/impala/planner/KuduScanNode.java: http://gerrit.cloudera.org:8080/#/c/16880/2/fe/src/main/java/org/apache/impala/planner/KuduScanNode.java@349 PS2, Line 349: cardinality_ == 0 I see this check came from HdfsScanNode, but I don't think it makes sense for Kudu. I think it'd be better to remove this and simplify this to something like. numNodes_ = Math.max(totalNodes, 1); http://gerrit.cloudera.org:8080/#/c/16880/2/fe/src/main/java/org/apache/impala/planner/KuduScanNode.java@359 PS2, Line 359: numInstances_ = Math.min(scanRangeSpecs_.getConcrete_rangesSize(), I think we should set this to totalInstances computed in computeNumNodes - it should be a more accurate estimate. -- To view, visit http://gerrit.cloudera.org:8080/16880 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I72e341597e980fb6a7e3792905b942ddf5797d03 Gerrit-Change-Number: 16880 Gerrit-PatchSet: 2 Gerrit-Owner: Akos Kovacs <[email protected]> Gerrit-Reviewer: Impala Public Jenkins <[email protected]> Gerrit-Reviewer: Tim Armstrong <[email protected]> Gerrit-Comment-Date: Thu, 07 Jan 2021 17:22:54 +0000 Gerrit-HasComments: Yes
