godfrey he created FLINK-16195: ---------------------------------- Summary: append constant field to unique key set on project when deriving unique keys in FlinkRelMdUniqueKeys Key: FLINK-16195 URL: https://issues.apache.org/jira/browse/FLINK-16195 Project: Flink Issue Type: Improvement Components: Table SQL / Planner Reporter: godfrey he
currently, `FlinkRelMdUniqueKeys` only supports deriving unique keys on non-constant fields. such as: `select a, b, 1, count(*) from T group by a, b`, currently the derived unique keys is `a, b`. However `a, b, 1` is also a unique key, and the result is `a, b` and `a, b, 1`. note: Ideally, the planner does not require the constant key in the unique key set, all constant values are pulled up or removed as much as possible. Supports this improvement to handle some corner cases in cbo. -- This message was sent by Atlassian Jira (v8.3.4#803005)