[SPARK-14855][SQL] Add "Exec" suffix to physical operators

## What changes were proposed in this pull request?
This patch adds "Exec" suffix to all physical operators. Before this patch, Spark's physical operators and logical operators are named the same (e.g. Project could be logical.Project or execution.Project), which caused small issues in code review and bigger issues in code refactoring.

## How was this patch tested?
N/A

Author: Reynold Xin <rxin@databricks.com>

Closes #12617 from rxin/exec-node.

1 files changed, 6 insertions, 3 deletions

diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/trees/TreeNode.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/trees/TreeNode.scala
index 232ca43588..3d0e016a09 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/trees/TreeNode.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/trees/TreeNode.scala
@@ -408,8 +408,11 @@ abstract class TreeNode[BaseType <: TreeNode[BaseType]] extends Product {
     }
   }
 
-  /** Returns the name of this type of TreeNode.  Defaults to the class name. */
-  def nodeName: String = getClass.getSimpleName
+  /**
+   * Returns the name of this type of TreeNode.  Defaults to the class name.
+   * Note that we remove the "Exec" suffix for physical operators here.
+   */
+  def nodeName: String = getClass.getSimpleName.replaceAll("Exec$", "")
 
   /**
    * The arguments that should be included in the arg string.  Defaults to the `productIterator`.
@@ -426,7 +429,7 @@ abstract class TreeNode[BaseType <: TreeNode[BaseType]] extends Product {
     case other => other :: Nil
   }.mkString(", ")
 
-  /** String representation of this node without any children */
+  /** String representation of this node without any children. */
   def simpleString: String = s"$nodeName $argString".trim
 
   override def toString: String = treeString