backward compatibility

Author: zhztheplayer

sql/core/src/main/scala/org/apache/spark/sql/execution/columnar/InMemoryRelation.scala

@@ -381,6 +381,10 @@ object InMemoryRelation {
   /* Visible for testing */
   private[columnar] def clearSerializer(): Unit = synchronized { ser = None }
 
+  def convertToColumnarIfPossible(plan: SparkPlan): SparkPlan = {
+    getSerializer(plan.conf).convertToColumnarPlanIfPossible(plan)
+  }
+
   def apply(
       storageLevel: StorageLevel,
       qe: QueryExecution,