HyukjinKwon commented on code in PR #50301:
URL: https://github.com/apache/spark/pull/50301#discussion_r2000018806


##########
sql/core/src/main/scala/org/apache/spark/sql/execution/python/PythonArrowOutput.scala:
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@@ -83,17 +89,37 @@ private[python] trait PythonArrowOutput[OUT <: AnyRef] { 
self: BasePythonRunner[
           throw writer.exception.get
         }
         try {
-          if (reader != null && batchLoaded) {
+          if (batchLoaded && rowCount > 0 && currentRowIdx < rowCount) {
+            val batchRoot = if (arrowMaxRecordsPerOutputBatch > 0) {
+              val remainingRows = rowCount - currentRowIdx
+              if (remainingRows > arrowMaxRecordsPerOutputBatch) {
+                root.slice(currentRowIdx, arrowMaxRecordsPerOutputBatch)
+              } else {
+                root
+              }
+            } else {
+              root
+            }
+
+            currentRowIdx = currentRowIdx + batchRoot.getRowCount
+
+            vectors = batchRoot.getFieldVectors().asScala.map { vector =>
+              new ArrowColumnVector(vector)
+            }.toArray[ColumnVector]
+
+            val batch = new ColumnarBatch(vectors)
+            batch.setNumRows(batchRoot.getRowCount)
+            deserializeColumnarBatch(batch, schema)

Review Comment:
   BTW, ideally we should slices the batch at Python worker side. With the 
number of records, it should be feasible.
   
   Separately, I wonder if we should limit the size by bytes ..but in this case 
the problem is that it is difficult to get the byte size from pandas instances 
(so it is difficult to slice pandas instances before converting it to Arrow 
batch). 



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