Li Xian created SPARK-39429: ------------------------------- Summary: Convert Inner Join With Aggregate To Semi Join Key: SPARK-39429 URL: https://issues.apache.org/jira/browse/SPARK-39429 Project: Spark Issue Type: Improvement Components: Optimizer Affects Versions: 3.2.1 Reporter: Li Xian
Inner Join with aggregation on one of its child it equivalent to a Semi Join with the aggregation eliminated If the aggregation is just doing grouping and all the grouping columns appears in the join condition. For example, Inner Join like below {code:java} select * from table1 inner join (select key2 from table2 group by key2) subquery on table1.key1 = subquery.key2{code} can be transformed to a semi join and eliminate the aggregate in the subquery {code:java} select * from table1 semi join (select key2 from table2) subquery on table1.key1 = subquery.key2 {code} I think this can be added as a optimize rule to save the unnecessary aggregation in the subquery. -- This message was sent by Atlassian Jira (v8.20.7#820007) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org