diff --git a/cpp/src/db/MemTableFile.cpp b/cpp/src/db/MemTableFile.cpp
index 649a680cf3efba076fffdab47896ac22b986dd6e..fb77a6ac3f29e7db66f74e0321abbaee843a3d24 100644
--- a/cpp/src/db/MemTableFile.cpp
+++ b/cpp/src/db/MemTableFile.cpp
@@ -103,6 +103,32 @@ Status MemTableFile::Serialize() {
     return status;
 }
 
+Status MemTableFile::Serialize() {
+
+    auto start_time = METRICS_NOW_TIME;
+
+    auto size = GetCurrentMem();
+
+    execution_engine_->Serialize();
+    auto end_time = METRICS_NOW_TIME;
+    auto total_time = METRICS_MICROSECONDS(start_time, end_time);
+    table_file_schema_.size_ = size;
+
+    server::Metrics::GetInstance().DiskStoreIOSpeedGaugeSet((double)size/total_time);
+
+    table_file_schema_.file_type_ = (size >= options_.index_trigger_size) ?
+                         meta::TableFileSchema::TO_INDEX : meta::TableFileSchema::RAW;
+
+    auto status = meta_->UpdateTableFile(table_file_schema_);
+
+    LOG(DEBUG) << "New " << ((table_file_schema_.file_type_ == meta::TableFileSchema::RAW) ? "raw" : "to_index")
+               << " file " << table_file_schema_.file_id_ << " of size " << (double)size / (double)M << " M";
+
+    execution_engine_->Cache();
+
+    return status;
+}
+
 } // namespace engine
 } // namespace milvus
 } // namespace zilliz
\ No newline at end of file
diff --git a/cpp/src/db/VectorSource.cpp b/cpp/src/db/VectorSource.cpp
index 74c07ae1f67a54e4301474a2d350091ce196de3b..52b3e403422957688033ab7c334d77d6ea816925 100644
--- a/cpp/src/db/VectorSource.cpp
+++ b/cpp/src/db/VectorSource.cpp
@@ -4,7 +4,6 @@
 #include "Log.h"
 #include "metrics/Metrics.h"
 
-
 namespace zilliz {
 namespace milvus {
 namespace engine {
diff --git a/cpp/unittest/db/mem_test.cpp b/cpp/unittest/db/mem_test.cpp
index 5b7972ec35f92375558bf26a2d5bcdae4e2ac11e..6925dba1eb0f93c648a050b2c8b7e487c7628c24 100644
--- a/cpp/unittest/db/mem_test.cpp
+++ b/cpp/unittest/db/mem_test.cpp
@@ -146,11 +146,7 @@ TEST_F(NewMemManagerTest, MEM_TABLE_TEST) {
 
     engine::VectorSource::Ptr source_100 = std::make_shared<engine::VectorSource>(n_100, vectors_100.data());
 
-    engine::MemTable mem_table(TABLE_NAME, impl_, options);
-
-    status = mem_table.Add(source_100);
     ASSERT_TRUE(status.ok());
-
     engine::IDNumbers vector_ids = source_100->GetVectorIds();
     ASSERT_EQ(vector_ids.size(), 100);
 
@@ -193,6 +189,9 @@ TEST_F(NewMemManagerTest, MEM_TABLE_TEST) {
     status = mem_table.Serialize();
     ASSERT_TRUE(status.ok());
 
+    status = memTable.Serialize();
+    ASSERT_TRUE(status.ok());
+
     status = impl_->DropAll();
     ASSERT_TRUE(status.ok());
 }