Temp test

cpp/velox/compute/iceberg/IcebergWriter.cc

@@ -236,15 +236,42 @@ void IcebergWriter::write(const VeloxColumnarBatch& batch) {
   auto inputRowVector = batch.getRowVector();
   auto inputRowType = asRowType(inputRowVector->type());
 
+  // Filter columns to match the expected schema (rowType_)
+  // This is needed because Spark 4.0 adds metadata columns like __row_operation, _file, _pos
+  // which are not part of the Iceberg write schema
   if (inputRowType->size() != rowType_->size()) {
-    const auto& children = inputRowVector->children();
-    std::vector<VectorPtr> dataColumns(children.begin() + 1, children.begin() + 1 + rowType_->size());
+    std::vector<VectorPtr> filteredChildren;
+    filteredChildren.reserve(rowType_->size());
 
+    // Build a map of column names to indices in the input
+    std::unordered_map<std::string, size_t> inputColumnIndices;
+    for (size_t i = 0; i < inputRowType->size(); i++) {
+      inputColumnIndices[inputRowType->nameOf(i)] = i;
+    }
+
+    // Extract columns in the order specified by rowType_
+    for (size_t i = 0; i < rowType_->size(); i++) {
+      const auto& columnName = rowType_->nameOf(i);
+      auto it = inputColumnIndices.find(columnName);
+      VELOX_CHECK(
+          it != inputColumnIndices.end(),
+          "Column '{}' not found in input batch. Available columns: {}",
+          columnName,
+          folly::join(", ", inputRowType->names()));
+      filteredChildren.push_back(inputRowVector->childAt(it->second));
+    }
+
+    // Create a new RowVector with filtered columns
     auto filteredRowVector = std::make_shared<RowVector>(
-        pool_.get(), rowType_, inputRowVector->nulls(), inputRowVector->size(), std::move(dataColumns));
+        pool_.get(),
+        rowType_,
+        inputRowVector->nulls(),
+        inputRowVector->size(),
+        std::move(filteredChildren));
 
     dataSink_->appendData(filteredRowVector);
   } else {
+    // No filtering needed, schemas match
     dataSink_->appendData(inputRowVector);
   }
 }