diff --git a/core/src/server/grpc_impl/GrpcRequestHandler.cpp b/core/src/server/grpc_impl/GrpcRequestHandler.cpp
index 076f23a140..5a0636b0d1 100644
--- a/core/src/server/grpc_impl/GrpcRequestHandler.cpp
+++ b/core/src/server/grpc_impl/GrpcRequestHandler.cpp
@@ -460,9 +460,7 @@ GrpcRequestHandler::Search(::grpc::ServerContext* context, const ::milvus::grpc:
 
     // step 2: partition tags
     std::vector<std::string> partitions;
-    for (auto& partition : request->partition_tag_array()) {
-        partitions.emplace_back(partition);
-    }
+    std::copy(request->partition_tag_array().begin(), request->partition_tag_array().end(), std::back_inserter(partitions));
 
     // step 3: parse extra parameters
     milvus::json json_params;