From 83589915eff9a60a757ad353c1e864c1b703dfbf Mon Sep 17 00:00:00 2001
From: Zhen Li <10524738+zhli1142015@users.noreply.github.com>
Date: Tue, 20 Jun 2023 20:46:20 +0800
Subject: [PATCH] Add flag for sort in window (#321)

* add flag for sort in window op

* minor change
---
 velox/exec/Window.cpp | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/velox/exec/Window.cpp b/velox/exec/Window.cpp
index dd95bb9cd915..c5b11ce1fbb2 100644
--- a/velox/exec/Window.cpp
+++ b/velox/exec/Window.cpp
@@ -17,6 +17,8 @@
 #include "velox/exec/OperatorUtils.h"
 #include "velox/exec/Task.h"
 
+DEFINE_bool(SkipRowSortInWindowOp, false, "Skip row sort");
+
 namespace facebook::velox::exec {
 
 namespace {
@@ -277,13 +279,14 @@ void Window::sortPartitions() {
   sortedRows_.resize(numRows_);
   RowContainerIterator iter;
   data_->listRows(&iter, numRows_, sortedRows_.data());
-
-  std::sort(
-      sortedRows_.begin(),
-      sortedRows_.end(),
-      [this](const char* leftRow, const char* rightRow) {
-        return compareRowsWithKeys(leftRow, rightRow, allKeyInfo_);
-      });
+  if (!FLAGS_SkipRowSortInWindowOp) {
+    std::sort(
+        sortedRows_.begin(),
+        sortedRows_.end(),
+        [this](const char* leftRow, const char* rightRow) {
+          return compareRowsWithKeys(leftRow, rightRow, allKeyInfo_);
+        });
+  }
 
   computePartitionStartRows();