Github user gatorsmile commented on a diff in the pull request:
https://github.com/apache/spark/pull/17353#discussion_r106841523
--- Diff:
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/CostBasedJoinReorder.scala
---
@@ -202,14 +201,15 @@ object JoinReorderDP extends PredicateHelper {
}
/**
- * Builds a new JoinPlan if the two given sides can be joined with some
conditions.
+ * Builds a new JoinPlan if there exists at least one join condition
involving references from
+ * both left and right.
* @param oneJoinPlan One side JoinPlan for building a new JoinPlan.
* @param otherJoinPlan The other side JoinPlan for building a new join
node.
* @param conf SQLConf for statistics computation.
* @param conditions The overall set of join conditions.
* @param topOutput The output attributes of the final plan.
- * @return Return a new JoinPlan if the two sides can be joined with
some conditions. Otherwise,
- * return None.
+ * @return Builds and returns a new JoinPlan if there exists at least
one join condition
+ * involving references from both left and right. Otherwise,
returns None.
--- End diff --
Now, we can simplify it to `Builds and returns a new JoinPlan if both
conditions hold. Otherwise, returns None.`
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastruct...@apache.org or file a JIRA ticket
with INFRA.
---
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org
For additional commands, e-mail: reviews-h...@spark.apache.org
