diff --git a/cpp/velox/benchmarks/QueryBenchmark.cc b/cpp/velox/benchmarks/QueryBenchmark.cc
index 791f2540b1e21..8ad8fbe3ba112 100644
--- a/cpp/velox/benchmarks/QueryBenchmark.cc
+++ b/cpp/velox/benchmarks/QueryBenchmark.cc
@@ -30,6 +30,34 @@ const std::string getFilePath(const std::string& fileName) {
   return filePath;
 }
 
+// Used by unit test and benchmark.
+std::shared_ptr<ResultIterator> getResultIterator(
+    MemoryAllocator* allocator,
+    std::shared_ptr<Backend> backend,
+    const std::vector<std::shared_ptr<velox::substrait::SplitInfo>>& setScanInfos,
+    std::shared_ptr<const facebook::velox::core::PlanNode>& veloxPlan) {
+  auto veloxPool = asWrappedVeloxAggregateMemoryPool(allocator);
+  auto ctxPool =veloxPool->addAggregateChild("query_benchmark_result_iterator");
+  auto resultPool = getDefaultVeloxLeafMemoryPool();
+
+  std::vector<std::shared_ptr<ResultIterator>> inputIter;
+  auto veloxPlanConverter = std::make_unique<VeloxPlanConverter>(inputIter, resultPool);
+  veloxPlan = veloxPlanConverter->toVeloxPlan(backend->getPlan());
+
+  // In test, use setScanInfos to replace the one got from Substrait.
+  std::vector<std::shared_ptr<velox::substrait::SplitInfo>> scanInfos;
+  std::vector<velox::core::PlanNodeId> scanIds;
+  std::vector<velox::core::PlanNodeId> streamIds;
+
+  // Separate the scan ids and stream ids, and get the scan infos.
+  VeloxBackend::getInfoAndIds(
+      veloxPlanConverter->splitInfos(), veloxPlan->leafPlanNodeIds(), scanInfos, scanIds, streamIds);
+
+  auto wholestageIter = std::make_unique<WholeStageResultIteratorFirstStage>(
+      ctxPool, resultPool, veloxPlan, scanIds, setScanInfos, streamIds, "/tmp/test-spill", backend->getConfMap());
+  return std::make_shared<ResultIterator>(std::move(wholestageIter), backend);
+}
+
 auto bm = [](::benchmark::State& state,
              const std::vector<std::string>& datasetPaths,
              const std::string& jsonFile,
@@ -52,17 +80,20 @@ auto bm = [](::benchmark::State& state,
       scanInfos.emplace_back(getSplitInfosFromFile(datasetPath, fileFormat));
       std::cout << "== not /" << std::endl;
     }
+    std::cout << datasetPath << std::endl;
   }
 
   for (auto _ : state) {
     state.PauseTiming();
     auto backend = std::dynamic_pointer_cast<gluten::VeloxBackend>(gluten::createBackend());
     state.ResumeTiming();
+
     backend->parsePlan(plan->data(), plan->size());
-    auto resultIter = backend->getResultIterator(gluten::defaultMemoryAllocator().get(), scanInfos);
-    auto outputSchema = backend->GetOutputSchema();
-    while (resultIter->HasNext()) {
-      auto array = resultIter->Next()->exportArrowArray();
+    std::shared_ptr<const facebook::velox::core::PlanNode> veloxPlan;
+    auto resultIter = getResultIterator(gluten::defaultMemoryAllocator().get(), backend, scanInfos, veloxPlan);
+    auto outputSchema = getOutputSchema(veloxPlan);
+    while (resultIter->hasNext()) {
+      auto array = resultIter->next()->exportArrowArray();
       auto maybeBatch = arrow::ImportRecordBatch(array.get(), outputSchema);
       if (!maybeBatch.ok()) {
         state.SkipWithError(maybeBatch.status().message().c_str());