Shant Hovsepian has posted comments on this change. ( http://gerrit.cloudera.org:8080/16349 )
Change subject: IMPALA-7310: Partial fix for NDV cardinality with NULLs. ...................................................................... Patch Set 8: (1 comment) > Patch Set 8: > > I wonder if the holes exposed by the current change can be remedied, for the > time being, by suppling a checkNull argument default to false which will > bypass the new logic. We call the new method with checkNull set to true in > SlotRef only. In the long run, we can fix these other issues. > > I am OK with reverting the logic to your previous version too if the chance > to hit the same problem for other expressions is low. Yeah having a check in slotRef to then just call a special method in stats is just not leaking the abstraction even more. I'd rather than just keep the change localized in slotref. http://gerrit.cloudera.org:8080/#/c/16349/8/testdata/workloads/functional-query/queries/QueryTest/compute-stats-date.test File testdata/workloads/functional-query/queries/QueryTest/compute-stats-date.test: http://gerrit.cloudera.org:8080/#/c/16349/8/testdata/workloads/functional-query/queries/QueryTest/compute-stats-date.test@32 PS8, Line 32: 'd','DATE',1,22,4,4,-1,-1 > Is this change right? I thought the column stats themselves were not meant Yeah this was originally why we only had the correction in the slotref so it benefits selectivity but nothing else. Having the correction in the stats class will show up everywhere stats are used. -- To view, visit http://gerrit.cloudera.org:8080/16349 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: Iec967053b4991f8c67cde62adf003cbd3f429032 Gerrit-Change-Number: 16349 Gerrit-PatchSet: 8 Gerrit-Owner: Shant Hovsepian <sh...@cloudera.com> Gerrit-Reviewer: Aman Sinha <amsi...@cloudera.com> Gerrit-Reviewer: David Rorke <dro...@cloudera.com> Gerrit-Reviewer: Impala Public Jenkins <impala-public-jenk...@cloudera.com> Gerrit-Reviewer: Qifan Chen <qc...@cloudera.com> Gerrit-Reviewer: Shant Hovsepian <sh...@cloudera.com> Gerrit-Reviewer: Tim Armstrong <tarmstr...@cloudera.com> Gerrit-Comment-Date: Sat, 29 Aug 2020 00:40:03 +0000 Gerrit-HasComments: Yes
