Optimize code

apache · Feb 10, 2020 · 5b3caa9 · 5b3caa9
1 parent c87069f
commit 5b3caa9
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Showing 2 changed files with 8 additions and 1 deletion.
diff --git a/...catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/windowExpressions.scala b/...catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/windowExpressions.scala
@@ -499,14 +499,16 @@ case class NthValue(input: Expression, offset: Expression)
     val check = super.checkInputDataTypes()
     if (check.isFailure) {
       check
-    } else {
+    } else if (offset.foldable) {
       offset.eval() match {
         case i: Int if i <= 0 => TypeCheckFailure(
           s"The 'offset' argument of nth_value must be greater than zero but it is $i.")
         case i: Int => TypeCheckSuccess
         case other => TypeCheckFailure(
           s"The 'offset' parameter must be a int literal but it is $other.")
       }
+    } else {
+      TypeCheckFailure("The 'offset' parameter must be a int literal.")
     }
   }
 }

diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/window/WindowFunctionFrame.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/window/WindowFunctionFrame.scala
@@ -157,6 +157,11 @@ class OffsetWindowFunctionFrame(
   override def currentUpperBound(): Int = throw new UnsupportedOperationException()
 }
 
+/**
+ * The fixed offset window frame calculates frames containing
+ * NTH_VALUE/FIRST_VALUE/LAST_VALUE statements.
+ * The fixed offset windwo frame return the same value for all rows in the window partition.
+ */
 class FixedOffsetWindowFunctionFrame(
     target: InternalRow,
     ordinal: Int,