[ https://issues.apache.org/jira/browse/CALCITE-4511?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
ASF GitHub Bot updated CALCITE-4511: ------------------------------------ Labels: pull-request-available (was: ) > The number of distinct values for constant columns should be 1 > -------------------------------------------------------------- > > Key: CALCITE-4511 > URL: https://issues.apache.org/jira/browse/CALCITE-4511 > Project: Calcite > Issue Type: Improvement > Components: core > Reporter: Liya Fan > Assignee: Liya Fan > Priority: Major > Labels: pull-request-available > Time Spent: 10m > Remaining Estimate: 0h > > Suppose we have a relation with 3 columns: {{(a, '1', '2')}}. The first > column comes from an underlying table, while the other two columns are > constants. > For this relation, we should have {{NDV(1) = 1}}, since column 1 is a > constant, which have only one possible value (suppose the column index starts > from 0). > Similarly, we should have {{NDV(1, 2) = 1}}, since both columns are constants. > We should also have {{NDV(0, 1) == NDV(0)}}, because the number of distinct > values depends on the non-const column, which is {{a}} from the underlying > table. -- This message was sent by Atlassian Jira (v8.3.4#803005)