remove suffix

Author: Davies Liu

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/BoundAttribute.scala

@@ -31,7 +31,7 @@ import org.apache.spark.sql.types._
 case class BoundReference(ordinal: Int, dataType: DataType, nullable: Boolean)
   extends LeafExpression with NamedExpression {
 
-  override def toString: String = s"input[$ordinal, $dataType]${if (nullable) "?" else ""}"
+  override def toString: String = s"input[$ordinal, $dataType]"
 
   // Use special getter for primitive types (for UnsafeRow)
   override def eval(input: InternalRow): Any = {

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/namedExpressions.scala

@@ -81,10 +81,9 @@ trait NamedExpression extends Expression {
 
   protected def typeSuffix =
     if (resolved) {
-      val suffix = if (nullable) "?" else ""
       dataType match {
-        case LongType => "L" + suffix
-        case _ => suffix
+        case LongType => "L"
+        case _ => ""
       }
     } else {
       ""