Refined SQLContext.emptyResult as an empty RDD[Row]

Author: liancheng

sql/core/src/main/scala/org/apache/spark/sql/SQLContext.scala

@@ -252,8 +252,7 @@ class SQLContext(@transient val sparkContext: SparkContext)
   protected[sql] val planner = new SparkPlanner
 
   @transient
-  protected[sql] lazy val emptyResult =
-    sparkContext.parallelize(Seq(new GenericRow(Array[Any]()): Row), 1)
+  protected[sql] lazy val emptyResult = sparkContext.parallelize(Seq.empty[Row], 1)
 
   /**
    * Prepares a planned SparkPlan for execution by binding references to specific ordinals, and