From 01f00aad6f1194d976d9a817a6a864ffbba28db4 Mon Sep 17 00:00:00 2001
From: Pxl <pxl290@qq.com>
Date: Mon, 15 Jul 2024 21:20:33 +0800
Subject: [PATCH] [Bug](bitmap) clear set when bitmap fastunion (#37816)

## Proposed changes
before:6 min 59.33 sec
after   :24.67 sec
---
 be/src/util/bitmap_value.h | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/be/src/util/bitmap_value.h b/be/src/util/bitmap_value.h
index ac5e826e1fee66..2d15ac99611274 100644
--- a/be/src/util/bitmap_value.h
+++ b/be/src/util/bitmap_value.h
@@ -1252,8 +1252,7 @@ class BitmapValue {
         std::vector<const detail::Roaring64Map*> bitmaps;
         std::vector<uint64_t> single_values;
         std::vector<const SetContainer<uint64_t>*> sets;
-        for (int i = 0; i < values.size(); ++i) {
-            auto* value = values[i];
+        for (const auto* value : values) {
             switch (value->_type) {
             case EMPTY:
                 break;
@@ -1280,7 +1279,9 @@ class BitmapValue {
                 _bitmap->add(_sv);
                 break;
             case BITMAP:
-                *_bitmap |= detail::Roaring64Map::fastunion(bitmaps.size(), bitmaps.data());
+                for (const auto* bitmap : bitmaps) {
+                    *_bitmap |= *bitmap;
+                }
                 break;
             case SET: {
                 *_bitmap = detail::Roaring64Map::fastunion(bitmaps.size(), bitmaps.data());
@@ -1315,6 +1316,7 @@ class BitmapValue {
                     _bitmap->add(v);
                 }
                 _type = BITMAP;
+                _set.clear();
                 break;
             case SET: {
                 break;