diff --git a/internal/core/src/segcore/reduce_c.cpp b/internal/core/src/segcore/reduce_c.cpp
index 5ba749d4536a9c9dafe9d93f3f62b2345c0a84ec..26ee6a7baaa7c5876dc8636c7f5c94fabdadfbd5 100644
--- a/internal/core/src/segcore/reduce_c.cpp
+++ b/internal/core/src/segcore/reduce_c.cpp
@@ -67,28 +67,31 @@ DeleteMarshaledHits(CMarshaledHits c_marshaled_hits) {
 //}
 
 void
-GetResultData(std::vector<std::vector<int64_t>>& search_records,
-              std::vector<SearchResult*>& search_results,
-              int64_t nq,
-              int64_t topk) {
+ReduceResultData(std::vector<SearchResult*>& search_results, int64_t nq, int64_t topk) {
     AssertInfo(topk > 0, "topk must greater than 0");
     auto num_segments = search_results.size();
     AssertInfo(num_segments > 0, "num segment must greater than 0");
+    for (int i = 0; i < num_segments; i++) {
+        auto search_result = search_results[i];
+        AssertInfo(search_result != nullptr, "search result must not equal to nullptr");
+        AssertInfo(search_result->primary_keys_.size() == nq * topk, "incorrect search result primary key size");
+        AssertInfo(search_result->result_distances_.size() == nq * topk, "incorrect search result distance size");
+    }
 
+    std::vector<std::vector<int64_t>> search_records(num_segments);
     std::unordered_set<int64_t> pk_set;
     int64_t skip_dup_cnt = 0;
+
+    // reduce search results
     for (int64_t qi = 0; qi < nq; qi++) {
         std::vector<SearchResultPair> result_pairs;
         int64_t base_offset = qi * topk;
-        for (int j = 0; j < num_segments; ++j) {
-            auto search_result = search_results[j];
-            AssertInfo(search_result != nullptr, "search result must not equal to nullptr");
-            AssertInfo(search_result->primary_keys_.size() == nq * topk, "incorrect search result primary key size");
-            AssertInfo(search_result->result_distances_.size() == nq * topk, "incorrect search result distance size");
+        for (int i = 0; i < num_segments; i++) {
+            auto search_result = search_results[i];
             auto primary_key = search_result->primary_keys_[base_offset];
             auto distance = search_result->result_distances_[base_offset];
             result_pairs.push_back(
-                SearchResultPair(primary_key, distance, search_result, j, base_offset, base_offset + topk));
+                SearchResultPair(primary_key, distance, search_result, i, base_offset, base_offset + topk));
         }
         int64_t curr_offset = base_offset;
 
@@ -125,18 +128,11 @@ GetResultData(std::vector<std::vector<int64_t>>& search_records,
         }
 #endif
     }
-    if (skip_dup_cnt > 0) {
-        LOG_SEGCORE_DEBUG_ << "skip duplicated search result, count = " << skip_dup_cnt;
-    }
-}
+    LOG_SEGCORE_DEBUG_ << "skip duplicated search result, count = " << skip_dup_cnt;
 
-void
-ResetSearchResult(std::vector<std::vector<int64_t>>& search_records, std::vector<SearchResult*>& search_results) {
-    auto num_segments = search_results.size();
-    AssertInfo(num_segments > 0, "num segment must greater than 0");
+    // after reduce, remove redundant values in primary_keys, result_distances and internal_seg_offsets
     for (int i = 0; i < num_segments; i++) {
         auto search_result = search_results[i];
-        AssertInfo(search_result != nullptr, "search result must not equal to nullptr");
         if (search_result->result_offsets_.size() == 0) {
             continue;
         }
@@ -144,23 +140,12 @@ ResetSearchResult(std::vector<std::vector<int64_t>>& search_records, std::vector
         std::vector<int64_t> primary_keys;
         std::vector<float> result_distances;
         std::vector<int64_t> internal_seg_offsets;
-        int64_t primary_key;
-        float distance;
-        int64_t internal_seg_offset;
         for (int j = 0; j < search_records[i].size(); j++) {
             auto& offset = search_records[i][j];
-            if (offset != INVALID_OFFSET) {
-                primary_key = search_result->primary_keys_[offset];
-                distance = search_result->result_distances_[offset];
-                internal_seg_offset = search_result->internal_seg_offsets_[offset];
-            } else {
-                primary_key = INVALID_ID;
-                distance = MAXFLOAT;
-                internal_seg_offset = INVALID_SEG_OFFSET;
-            }
-            primary_keys.push_back(primary_key);
-            result_distances.push_back(distance);
-            internal_seg_offsets.push_back(internal_seg_offset);
+            primary_keys.push_back(offset != INVALID_OFFSET ? search_result->primary_keys_[offset] : INVALID_ID);
+            result_distances.push_back(offset != INVALID_OFFSET ? search_result->result_distances_[offset] : MAXFLOAT);
+            internal_seg_offsets.push_back(offset != INVALID_OFFSET ? search_result->internal_seg_offsets_[offset]
+                                                                    : INVALID_SEG_OFFSET);
         }
 
         search_result->primary_keys_ = primary_keys;
@@ -179,7 +164,6 @@ ReduceSearchResultsAndFillData(CSearchPlan c_plan, CSearchResult* c_search_resul
         }
         auto topk = search_results[0]->topk_;
         auto num_queries = search_results[0]->num_queries_;
-        std::vector<std::vector<int64_t>> search_records(num_segments);
 
         // get primary keys for duplicates removal
         for (auto& search_result : search_results) {
@@ -187,8 +171,7 @@ ReduceSearchResultsAndFillData(CSearchPlan c_plan, CSearchResult* c_search_resul
             segment->FillPrimaryKeys(plan, *search_result);
         }
 
-        GetResultData(search_records, search_results, num_queries, topk);
-        ResetSearchResult(search_records, search_results);
+        ReduceResultData(search_results, num_queries, topk);
 
         // fill in other entities
         for (auto& search_result : search_results) {