diff --git a/example/keyword_pir_db_build_task_conf.json b/example/keyword_pir_db_build_task_conf.json
index b67a101e..ff2dc373 100644
--- a/example/keyword_pir_db_build_task_conf.json
+++ b/example/keyword_pir_db_build_task_conf.json
@@ -13,9 +13,9 @@
       "value": 1
     },
     "DbInfo": {
-      "description": "create sender db offline",
+      "description": "create sender db offline, format of file_name: concat datasetid with key columns, seperated by _",
       "type": "STRING",
-      "value": "data/cache/keyword_pir_server_data"
+      "value": "data/cache/keyword_pir_server_data_0_1"
     },
     "QueryConfig": {
       "type": "OBJECT",
diff --git a/src/primihub/task/semantic/pir_task.cc b/src/primihub/task/semantic/pir_task.cc
index 54ad81a6..c125f234 100644
--- a/src/primihub/task/semantic/pir_task.cc
+++ b/src/primihub/task/semantic/pir_task.cc
@@ -66,12 +66,16 @@ retcode PirTask::BuildOptions(const rpc::Task& task, pir::Options* options) {
         auto it = param_map.find(party_name());
         if (it != param_map.end()) {
           options->db_path.append(it->second.value_string());
+
         } else {
           LOG(ERROR) << "dateset id is not set";
           return retcode::FAIL;
         }
       } else {
-         options->db_path.append(this->dataset_id_);
+        options->db_path.append(this->dataset_id_);
+      }
+      for (const auto key_index : this->server_key_columns_) {
+        options->db_path.append("_").append(std::to_string(key_index));
       }
 
       if (DbCacheAvailable(options->db_path)) {