[GitHub] [spark] ulysses-you commented on a diff in pull request #36530: [SPARK-39172][SQL] Remove outer join if all output come from streamed side and buffered side keys exist unique key

[GitBox <gi...@apache.org>]

ulysses-you commented on code in PR #36530:
URL: https://github.com/apache/spark/pull/36530#discussion_r873491017


##########
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/joins.scala:
##########
@@ -139,6 +139,14 @@ object ReorderJoin extends Rule[LogicalPlan] with PredicateHelper {
  *   SELECT t1.c1, max(t1.c2) FROM t1 GROUP BY t1.c1
  * }}}
  *
+ * 3. Remove outer join if all output comes from streamed side and the join keys from buffered side
+ * exist unique key.

Review Comment:
   changed it to 
   
   ```
    * 3. Remove outer join if:
    *   - For a left outer join with only left-side columns being selected and the right side join
    *     keys are unique.
    *   - For a right outer join with only right-side columns being selected and the left side join
    *     keys are unique.
   ```



-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org

For queries about this service, please contact Infrastructure at:
users@infra.apache.org


---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org