Github user gatorsmile commented on a diff in the pull request:
https://github.com/apache/spark/pull/11599#discussion_r55482347
--- Diff:
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/Optimizer.scala
---
@@ -380,6 +380,9 @@ object ColumnPruning extends Rule[LogicalPlan] {
p
}
+ // Eliminate the Projects with empty projectList
+ case p @ Project(projectList, child) if projectList.isEmpty => child
--- End diff --
Let me respond the original question by @cloud-fan
We will not see an empty Project, if the child has more than one columns.
The empty Project only happens after columnPruning. I am fine, if we want to
add an extra rule for eliminating Project only.
---
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
