diff --git a/internal/core/src/common/FieldMeta.h b/internal/core/src/common/FieldMeta.h
index 48e5024e14..6ef5856b84 100644
--- a/internal/core/src/common/FieldMeta.h
+++ b/internal/core/src/common/FieldMeta.h
@@ -218,7 +218,7 @@ class FieldMeta {
         : name_(name),
           id_(id),
           type_(type),
-          vector_info_(VectorInfo{dim, metric_type}) {
+          vector_info_(VectorInfo{dim, std::move(metric_type)}) {
         Assert(datatype_is_vector(type_));
     }
 
diff --git a/internal/core/src/exec/Driver.h b/internal/core/src/exec/Driver.h
index 12d1228a7c..693812a61f 100644
--- a/internal/core/src/exec/Driver.h
+++ b/internal/core/src/exec/Driver.h
@@ -78,7 +78,7 @@ class BlockingState {
                   ContinueFuture&& future,
                   Operator* op,
                   BlockingReason reason)
-        : driver_(std::move(driver_)),
+        : driver_(std::move(driver)),
           future_(std::move(future)),
           operator_(op),
           reason_(reason) {
diff --git a/internal/core/src/exec/Task.cpp b/internal/core/src/exec/Task.cpp
index 2b643c71e8..28abe68743 100644
--- a/internal/core/src/exec/Task.cpp
+++ b/internal/core/src/exec/Task.cpp
@@ -19,6 +19,7 @@
 #include <boost/lexical_cast.hpp>
 #include <boost/uuid/uuid_generators.hpp>
 #include <boost/uuid/uuid_io.hpp>
+#include "log/Log.h"
 
 namespace milvus {
 namespace exec {
@@ -139,6 +140,7 @@ Task::Next(ContinueFuture* future) {
                "Task has already finished processing.");
 
     if (driver_factories_.empty()) {
+        LOG_SEGCORE_WARNING_ << "create driver...";
         AssertInfo(
             consumer_supplier_ == nullptr,
             "Single-threaded execution doesn't support delivering results to a "
@@ -163,6 +165,7 @@ Task::Next(ContinueFuture* future) {
         CreateDriversLocked(self, kUngroupedGroupId, drivers);
 
         drivers_ = std::move(drivers);
+        LOG_SEGCORE_WARNING_ << "create driver done";
     }
 
     const auto num_drivers = drivers_.size();
@@ -188,7 +191,9 @@ Task::Next(ContinueFuture* future) {
 
             std::shared_ptr<BlockingState> blocking_state;
 
+            LOG_SEGCORE_WARNING_ << "driver fetch next result...";
             auto result = drivers_[i]->Next(blocking_state);
+            LOG_SEGCORE_WARNING_ << "driver fetch next result done";
 
             if (result) {
                 return result;
diff --git a/internal/core/src/index/ScalarIndexSort.cpp b/internal/core/src/index/ScalarIndexSort.cpp
index a96642e591..d69ac0df15 100644
--- a/internal/core/src/index/ScalarIndexSort.cpp
+++ b/internal/core/src/index/ScalarIndexSort.cpp
@@ -82,7 +82,7 @@ ScalarIndexSort<T>::BuildV2(const Config& config) {
         field_datas.push_back(field_data);
     }
     int64_t total_num_rows = 0;
-    for (auto data : field_datas) {
+    for (const auto& data : field_datas) {
         total_num_rows += data->get_num_rows();
     }
     if (total_num_rows == 0) {
@@ -92,7 +92,7 @@ ScalarIndexSort<T>::BuildV2(const Config& config) {
 
     data_.reserve(total_num_rows);
     int64_t offset = 0;
-    for (auto data : field_datas) {
+    for (const auto& data : field_datas) {
         auto slice_num = data->get_num_rows();
         for (size_t i = 0; i < slice_num; ++i) {
             auto value = reinterpret_cast<const T*>(data->RawValue(i));
@@ -122,7 +122,7 @@ ScalarIndexSort<T>::Build(const Config& config) {
         file_manager_->CacheRawDataToMemory(insert_files.value());
 
     int64_t total_num_rows = 0;
-    for (auto data : field_datas) {
+    for (const auto& data : field_datas) {
         total_num_rows += data->get_num_rows();
     }
     if (total_num_rows == 0) {
@@ -132,7 +132,7 @@ ScalarIndexSort<T>::Build(const Config& config) {
 
     data_.reserve(total_num_rows);
     int64_t offset = 0;
-    for (auto data : field_datas) {
+    for (const auto& data : field_datas) {
         auto slice_num = data->get_num_rows();
         for (size_t i = 0; i < slice_num; ++i) {
             auto value = reinterpret_cast<const T*>(data->RawValue(i));
diff --git a/internal/core/src/mmap/Utils.h b/internal/core/src/mmap/Utils.h
index 4a22a3981c..7b1dc8308d 100644
--- a/internal/core/src/mmap/Utils.h
+++ b/internal/core/src/mmap/Utils.h
@@ -34,7 +34,7 @@ namespace milvus {
 inline size_t
 GetDataSize(const std::vector<FieldDataPtr>& datas) {
     size_t total_size{0};
-    for (auto data : datas) {
+    for (const auto& data : datas) {
         total_size += data->Size();
     }
 
@@ -42,7 +42,7 @@ GetDataSize(const std::vector<FieldDataPtr>& datas) {
 }
 
 inline void*
-FillField(DataType data_type, const FieldDataPtr data, void* dst) {
+FillField(DataType data_type, const FieldDataPtr& data, void* dst) {
     char* dest = reinterpret_cast<char*>(dst);
     if (datatype_is_variable(data_type)) {
         switch (data_type) {