Jiajun Xie created CALCITE-6214: ----------------------------------- Summary: Remove `DISTINCT` in `COUNT` if field is unique Key: CALCITE-6214 URL: https://issues.apache.org/jira/browse/CALCITE-6214 Project: Calcite Issue Type: Improvement Components: core Reporter: Jiajun Xie Assignee: Jiajun Xie
For the sql {code:java} select count(distinct x) cnt from( select distinct sal x from emp ) t {code} The distinct that in count can be removed. {code:java} LogicalAggregate(group=[{}], CNT=[COUNT($0)]) LogicalAggregate(group=[{0}]) LogicalProject(X=[$5]) LogicalTableScan(table=[[CATALOG, SALES, EMP]]) {code} But `CoreRules#AGGREGATE_REMOVE` not support it, so there are two DISTINCT. {code:java} LogicalAggregate(group=[{}], CNT=[COUNT(DISTINCT $0)]) LogicalAggregate(group=[{0}]) LogicalProject(X=[$5]) LogicalTableScan(table=[[CATALOG, SALES, EMP]]) {code} -- This message was sent by Atlassian Jira (v8.20.10#820010)