diff --git a/cpp/src/db/Serializer.cpp b/cpp/src/db/ExecutionEngine.cpp
similarity index 77%
rename from cpp/src/db/Serializer.cpp
rename to cpp/src/db/ExecutionEngine.cpp
index 595cd4731c..9aea3f7ea1 100644
--- a/cpp/src/db/Serializer.cpp
+++ b/cpp/src/db/ExecutionEngine.cpp
@@ -1,11 +1,11 @@
 #include <easylogging++.h>
-#include "Serializer.h"
+#include "ExecutionEngine.h"
 
 namespace zilliz {
 namespace vecwise {
 namespace engine {
 
-Status Serializer::AddWithIds(const std::vector<float>& vectors, const std::vector<long>& vector_ids) {
+Status ExecutionEngine::AddWithIds(const std::vector<float>& vectors, const std::vector<long>& vector_ids) {
     long n1 = (long)vectors.size();
     long n2 = (long)vector_ids.size();
     if (n1 != n2) {
diff --git a/cpp/src/db/Serializer.h b/cpp/src/db/ExecutionEngine.h
similarity index 90%
rename from cpp/src/db/Serializer.h
rename to cpp/src/db/ExecutionEngine.h
index dcb32e0b05..4b08149f45 100644
--- a/cpp/src/db/Serializer.h
+++ b/cpp/src/db/ExecutionEngine.h
@@ -8,7 +8,7 @@ namespace zilliz {
 namespace vecwise {
 namespace engine {
 
-class Serializer {
+class ExecutionEngine {
 public:
 
     Status AddWithIds(const std::vector<float>& vectors,
@@ -24,7 +24,7 @@ public:
 
     virtual Status Cache() = 0;
 
-    virtual ~Serializer() {}
+    virtual ~ExecutionEngine() {}
 };
 
 
diff --git a/cpp/src/db/FaissSerializer.cpp b/cpp/src/db/FaissExecutionEngine.cpp
similarity index 66%
rename from cpp/src/db/FaissSerializer.cpp
rename to cpp/src/db/FaissExecutionEngine.cpp
index b2abb3a19c..ffa3ef3c24 100644
--- a/cpp/src/db/FaissSerializer.cpp
+++ b/cpp/src/db/FaissExecutionEngine.cpp
@@ -3,7 +3,7 @@
 #include <wrapper/Index.h>
 #include <cache/CpuCacheMgr.h>
 
-#include "FaissSerializer.h"
+#include "FaissExecutionEngine.h"
 
 namespace zilliz {
 namespace vecwise {
@@ -11,30 +11,30 @@ namespace engine {
 
 const std::string IndexType = "IDMap,Flat";
 
-FaissSerializer::FaissSerializer(uint16_t dimension, const std::string& location)
+FaissExecutionEngine::FaissExecutionEngine(uint16_t dimension, const std::string& location)
     : pIndex_(faiss::index_factory(dimension, IndexType.c_str())),
       location_(location) {
 }
 
-Status FaissSerializer::AddWithIds(long n, const float *xdata, const long *xids) {
+Status FaissExecutionEngine::AddWithIds(long n, const float *xdata, const long *xids) {
     pIndex_->add_with_ids(n, xdata, xids);
     return Status::OK();
 }
 
-size_t FaissSerializer::Count() const {
+size_t FaissExecutionEngine::Count() const {
     return (size_t)(pIndex_->ntotal);
 }
 
-size_t FaissSerializer::Size() const {
+size_t FaissExecutionEngine::Size() const {
     return (size_t)(Count() * pIndex_->d);
 }
 
-Status FaissSerializer::Serialize() {
+Status FaissExecutionEngine::Serialize() {
     write_index(pIndex_.get(), location_.c_str());
     return Status::OK();
 }
 
-Status FaissSerializer::Cache() {
+Status FaissExecutionEngine::Cache() {
     zilliz::vecwise::cache::CpuCacheMgr::GetInstance(
             )->InsertItem(location_, std::make_shared<Index>(pIndex_));
 
diff --git a/cpp/src/db/FaissSerializer.h b/cpp/src/db/FaissExecutionEngine.h
similarity index 78%
rename from cpp/src/db/FaissSerializer.h
rename to cpp/src/db/FaissExecutionEngine.h
index d3a255a0bb..bb1f5a4770 100644
--- a/cpp/src/db/FaissSerializer.h
+++ b/cpp/src/db/FaissExecutionEngine.h
@@ -3,7 +3,7 @@
 #include <memory>
 #include <string>
 
-#include "Serializer.h"
+#include "ExecutionEngine.h"
 
 namespace faiss {
     class Index;
@@ -13,9 +13,9 @@ namespace zilliz {
 namespace vecwise {
 namespace engine {
 
-class FaissSerializer : public Serializer {
+class FaissExecutionEngine : public ExecutionEngine {
 public:
-    FaissSerializer(uint16_t dimension, const std::string& location);
+    FaissExecutionEngine(uint16_t dimension, const std::string& location);
     virtual Status AddWithIds(long n, const float *xdata, const long *xids) override;
 
     virtual size_t Count() const override;
diff --git a/cpp/src/db/MemManager.cpp b/cpp/src/db/MemManager.cpp
index 88f1df7122..10ec582935 100644
--- a/cpp/src/db/MemManager.cpp
+++ b/cpp/src/db/MemManager.cpp
@@ -6,7 +6,7 @@
 
 #include "MemManager.h"
 #include "Meta.h"
-#include "FaissSerializer.h"
+#include "FaissExecutionEngine.h"
 
 
 namespace zilliz {
@@ -19,36 +19,36 @@ MemVectors::MemVectors(const std::shared_ptr<meta::Meta>& meta_ptr,
     options_(options),
     schema_(schema),
     _pIdGenerator(new SimpleIDGenerator()),
-    pSerializer_(new FaissSerializer(schema_.dimension, schema_.location)) {
+    pEE_(new FaissExecutionEngine(schema_.dimension, schema_.location)) {
 }
 
 void MemVectors::add(size_t n_, const float* vectors_, IDNumbers& vector_ids_) {
     _pIdGenerator->getNextIDNumbers(n_, vector_ids_);
-    pSerializer_->AddWithIds(n_, vectors_, vector_ids_.data());
+    pEE_->AddWithIds(n_, vectors_, vector_ids_.data());
     for(auto i=0 ; i<n_; i++) {
         vector_ids_.push_back(i);
     }
 }
 
 size_t MemVectors::total() const {
-    return pSerializer_->Count();
+    return pEE_->Count();
 }
 
 size_t MemVectors::approximate_size() const {
-    return pSerializer_->Size();
+    return pEE_->Size();
 }
 
 Status MemVectors::serialize(std::string& group_id) {
     group_id = schema_.group_id;
     auto rows = approximate_size();
-    pSerializer_->Serialize();
+    pEE_->Serialize();
     schema_.rows = rows;
     schema_.file_type = (rows >= options_.index_trigger_size) ?
         meta::GroupFileSchema::TO_INDEX : meta::GroupFileSchema::RAW;
 
     auto status = pMeta_->update_group_file(schema_);
 
-    pSerializer_->Cache();
+    pEE_->Cache();
 
     return status;
 }
diff --git a/cpp/src/db/MemManager.h b/cpp/src/db/MemManager.h
index e29b09817c..0a298bf22d 100644
--- a/cpp/src/db/MemManager.h
+++ b/cpp/src/db/MemManager.h
@@ -19,7 +19,7 @@ namespace meta {
     class Meta;
 }
 
-class Serializer;
+class ExecutionEngine;
 
 class MemVectors {
 public:
@@ -47,7 +47,7 @@ private:
     Options options_;
     meta::GroupFileSchema schema_;
     IDGenerator* _pIdGenerator;
-    std::shared_ptr<Serializer> pSerializer_;
+    std::shared_ptr<ExecutionEngine> pEE_;
 
 }; // MemVectors