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hvanhovell · hvanhovell · commit 7e30ae5222e8 · 2017-06-30T00:14:20.000+02:00
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/window/AggregateProcessor.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/window/AggregateProcessor.scala
@@ -145,6 +145,8 @@ private[window] final class AggregateProcessor(
 
   /** Update the buffer. */
   def update(input: InternalRow): Unit = {
+    // TODO(hvanhovell) this sacrifices performance for correctness. We should make sure that
+    // MutableProjection makes copies of the complex input objects it buffer.
     val copy = input.copy()
     updateProjection(join(buffer, copy))
     var i = 0
