diff --git a/cpp/src/cache/DataObj.h b/cpp/src/cache/DataObj.h
index 1dff04027e..995711c6ab 100644
--- a/cpp/src/cache/DataObj.h
+++ b/cpp/src/cache/DataObj.h
@@ -20,6 +20,11 @@ public:
             : index_(index)
     {}
 
+    DataObj(const engine::Index_ptr& index, int64_t size)
+            : index_(index),
+              size_(size)
+    {}
+
     engine::Index_ptr data() { return index_; }
     const engine::Index_ptr& data() const { return index_; }
 
@@ -28,11 +33,16 @@ public:
             return 0;
         }
 
+        if(size_ > 0) {
+            return size_;
+        }
+
         return index_->ntotal*(index_->dim*4);
     }
 
 private:
     engine::Index_ptr index_ = nullptr;
+    int64_t size_ = 0;
 };
 
 using DataObjPtr = std::shared_ptr<DataObj>;
diff --git a/cpp/src/db/DBImpl.cpp b/cpp/src/db/DBImpl.cpp
index beae6c30d3..5025c67adf 100644
--- a/cpp/src/db/DBImpl.cpp
+++ b/cpp/src/db/DBImpl.cpp
@@ -170,7 +170,10 @@ Status DBImpl::Query(const std::string& table_id, uint64_t k, uint64_t nq,
         }
     }
 
-    return QueryAsync(table_id, file_id_array, k, nq, vectors, dates, results);
+    cache::CpuCacheMgr::GetInstance()->PrintInfo(); //print cache info before query
+    status = QueryAsync(table_id, file_id_array, k, nq, vectors, dates, results);
+    cache::CpuCacheMgr::GetInstance()->PrintInfo(); //print cache info after query
+    return status;
 }
 
 Status DBImpl::Query(const std::string& table_id, const std::vector<std::string>& file_ids,
@@ -195,7 +198,10 @@ Status DBImpl::Query(const std::string& table_id, const std::vector<std::string>
         return Status::Error("Invalid file id");
     }
 
-    return QueryAsync(table_id, files_array, k, nq, vectors, dates, results);
+    cache::CpuCacheMgr::GetInstance()->PrintInfo(); //print cache info before query
+    status = QueryAsync(table_id, files_array, k, nq, vectors, dates, results);
+    cache::CpuCacheMgr::GetInstance()->PrintInfo(); //print cache info after query
+    return status;
 }
 
 Status DBImpl::QueryAsync(const std::string& table_id, const meta::TableFilesSchema& files,
diff --git a/cpp/src/db/FaissExecutionEngine.cpp b/cpp/src/db/FaissExecutionEngine.cpp
index 7183f43017..e32363dd1d 100644
--- a/cpp/src/db/FaissExecutionEngine.cpp
+++ b/cpp/src/db/FaissExecutionEngine.cpp
@@ -165,8 +165,9 @@ Status FaissExecutionEngine::Search(long n,
 }
 
 Status FaissExecutionEngine::Cache() {
-    zilliz::milvus::cache::CpuCacheMgr::GetInstance(
-            )->InsertItem(location_, std::make_shared<Index>(pIndex_));
+    auto index = std::make_shared<Index>(pIndex_);
+    cache::DataObjPtr data_obj = std::make_shared<cache::DataObj>(index, PhysicalSize());
+    zilliz::milvus::cache::CpuCacheMgr::GetInstance()->InsertItem(location_, data_obj);
 
     return Status::OK();
 }