Hi team, We are facing a scenario where two tables are outer joined but only fields from the outer side table are used and the join key of the inner side table is guaranteed to be unique. Take the following simplified query as an example, where s.id is guaranteed to be unique:
select t.* from t left join s on t.s_id = s.id; I noticed that Impala has supported a nonforced primary key in the create table statement (Ihttps://issues.apache.org/jira/browse/IMPALA-3531), we can utilize the nonforced primary key as a hint to eliminate the outer join to a simple scan on the outer side table. i.e, the above example can be optimized to: select t.* from t; Is there a plan to support this optimization in the community? If not, I'm willing to contribute to this. Best regards, Jian.
