From 21a9960acfc51b1ce87b1bfbd87cd9e2d01fd444 Mon Sep 17 00:00:00 2001
From: Yuan <yuanzhou@apache.org>
Date: Tue, 30 Sep 2025 15:01:59 +0100
Subject: [PATCH 1/2] [VL] Reduce memcpy in c2r

We always fill the buffer with 0 so it's no necessary to keep the old content when doing allocation in C2R

Signed-off-by: Yuan <yuanzhou@apache.org>
---
 .../operators/serializer/VeloxColumnarToRowConverter.cc  | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/cpp/velox/operators/serializer/VeloxColumnarToRowConverter.cc b/cpp/velox/operators/serializer/VeloxColumnarToRowConverter.cc
index 9a474f8141c6..b913765dc19a 100644
--- a/cpp/velox/operators/serializer/VeloxColumnarToRowConverter.cc
+++ b/cpp/velox/operators/serializer/VeloxColumnarToRowConverter.cc
@@ -57,14 +57,9 @@ void VeloxColumnarToRowConverter::refreshStates(facebook::velox::RowVectorPtr ro
     numRows_ = endRow - startRow;
   }
 
-  if (nullptr == veloxBuffers_) {
-    veloxBuffers_ = velox::AlignedBuffer::allocate<uint8_t>(totalMemorySize, veloxPool_.get());
-  } else if (veloxBuffers_->capacity() < totalMemorySize) {
-    velox::AlignedBuffer::reallocate<uint8_t>(&veloxBuffers_, totalMemorySize);
+  if (nullptr == veloxBuffers_ || veloxBuffers_->capacity() < totalMemorySize) {
+    veloxBuffers_ = velox::AlignedBuffer::allocate<uint8_t>(totalMemorySize, veloxPool_.get(), 0);
   }
-
-  bufferAddress_ = veloxBuffers_->asMutable<uint8_t>();
-  memset(bufferAddress_, 0, sizeof(int8_t) * totalMemorySize);
 }
 
 void VeloxColumnarToRowConverter::convert(std::shared_ptr<ColumnarBatch> cb, int64_t startRow) {

From 6dbe60e31337e856aa7767f6bba3e4c5b6d9e898 Mon Sep 17 00:00:00 2001
From: Yuan <yuanzhou@apache.org>
Date: Mon, 13 Oct 2025 11:47:31 -0400
Subject: [PATCH 2/2] fix

Signed-off-by: Yuan <yuanzhou@apache.org>
---
 .../operators/serializer/VeloxColumnarToRowConverter.cc      | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/cpp/velox/operators/serializer/VeloxColumnarToRowConverter.cc b/cpp/velox/operators/serializer/VeloxColumnarToRowConverter.cc
index b913765dc19a..f8977ee1bda9 100644
--- a/cpp/velox/operators/serializer/VeloxColumnarToRowConverter.cc
+++ b/cpp/velox/operators/serializer/VeloxColumnarToRowConverter.cc
@@ -58,8 +58,11 @@ void VeloxColumnarToRowConverter::refreshStates(facebook::velox::RowVectorPtr ro
   }
 
   if (nullptr == veloxBuffers_ || veloxBuffers_->capacity() < totalMemorySize) {
-    veloxBuffers_ = velox::AlignedBuffer::allocate<uint8_t>(totalMemorySize, veloxPool_.get(), 0);
+    veloxBuffers_ = velox::AlignedBuffer::allocate<uint8_t>(totalMemorySize, veloxPool_.get());
   }
+
+  bufferAddress_ = veloxBuffers_->asMutable<uint8_t>();
+  memset(bufferAddress_, 0, sizeof(int8_t) * totalMemorySize);
 }
 
 void VeloxColumnarToRowConverter::convert(std::shared_ptr<ColumnarBatch> cb, int64_t startRow) {