diff --git a/vectordb_bench/backend/assembler.py b/vectordb_bench/backend/assembler.py
index d945c299..a037af0f 100644
--- a/vectordb_bench/backend/assembler.py
+++ b/vectordb_bench/backend/assembler.py
@@ -54,7 +54,7 @@ def assemble_all(
             _ = k.init_cls
 
         # sort by dataset size
-        for k, _ in db2runner:
+        for k in db2runner:
             db2runner[k].sort(key=lambda x: x.ca.dataset.data.size)
 
         all_runners = []
diff --git a/vectordb_bench/backend/runner/mp_runner.py b/vectordb_bench/backend/runner/mp_runner.py
index d6ed282b..d967c9a3 100644
--- a/vectordb_bench/backend/runner/mp_runner.py
+++ b/vectordb_bench/backend/runner/mp_runner.py
@@ -220,7 +220,7 @@ def _run_by_dur(self, duration: int) -> tuple[float, float]:
 
                         qps = round(all_success_count / cost, 4)
                         log.info(
-                            f"End search in concurrency {conc}: dur={cost}s, failed_rate={failed_rate}"
+                            f"End search in concurrency {conc}: dur={cost}s, failed_rate={failed_rate}, "
                             f"all_success_count={all_success_count}, all_failed_count={all_failed_count}, qps={qps}",
                         )
                 if qps > max_qps:
diff --git a/vectordb_bench/interface.py b/vectordb_bench/interface.py
index 75279dc5..c4733cda 100644
--- a/vectordb_bench/interface.py
+++ b/vectordb_bench/interface.py
@@ -249,7 +249,7 @@ def _clear_running_task(self):
 
     def _run_async(self, conn: Connection) -> bool:
         log.info(
-            f"task submitted: id={self.running_task.run_id}, {self.running_task.task_label}, ",
+            f"task submitted: id={self.running_task.run_id}, {self.running_task.task_label}, "
             f"case number: {len(self.running_task.case_runners)}",
         )
         global global_result_future