diff --git a/vectordb_bench/backend/clients/cockroachdb/cockroachdb.py b/vectordb_bench/backend/clients/cockroachdb/cockroachdb.py
index dd4016d7f..1d20a350d 100644
--- a/vectordb_bench/backend/clients/cockroachdb/cockroachdb.py
+++ b/vectordb_bench/backend/clients/cockroachdb/cockroachdb.py
@@ -35,7 +35,7 @@ class CockroachDB(VectorDB):
         FilterOp.StrEqual,
     ]
 
-    def __init__(
+    def __init__(  # noqa: PLR0915
         self,
         dim: int,
         db_config: dict,
diff --git a/vectordb_bench/backend/runner/rate_runner.py b/vectordb_bench/backend/runner/rate_runner.py
index ecfc53862..c56c8ca61 100644
--- a/vectordb_bench/backend/runner/rate_runner.py
+++ b/vectordb_bench/backend/runner/rate_runner.py
@@ -7,7 +7,6 @@
 
 from vectordb_bench import config
 from vectordb_bench.backend.clients import api
-from vectordb_bench.backend.clients.doris.doris import Doris
 from vectordb_bench.backend.dataset import DataSetIterator
 from vectordb_bench.backend.utils import time_it
 
@@ -54,7 +53,7 @@ def _insert_embeddings(db: api.VectorDB, emb: list[list[float]], metadata: list[
             db_copy = deepcopy(db)
             with db_copy.init():
                 _insert_embeddings(db_copy, emb, metadata, retry_idx=0)
-        elif isinstance(db, Doris):
+        elif db.name == "Doris":
             # DorisVectorClient is not thread-safe. Similar to pgvector, create a per-thread client
             # by deep-copying the wrapper and forcing lazy re-init inside the thread.
             db_copy = deepcopy(db)