diff --git a/lightrag/constants.py b/lightrag/constants.py
index 26205689..a3773f63 100644
--- a/lightrag/constants.py
+++ b/lightrag/constants.py
@@ -26,6 +26,9 @@ DEFAULT_RELATED_CHUNK_NUMBER = 5
 # Separator for graph fields
 GRAPH_FIELD_SEP = "<SEP>"
 
+# File path configuration for vector and graph database
+DEFAULT_MAX_FILE_PATH_LENGTH = 4090
+
 # Logging configuration defaults
 DEFAULT_LOG_MAX_BYTES = 10485760  # Default 10MB
 DEFAULT_LOG_BACKUP_COUNT = 5  # Default 5 backups
diff --git a/lightrag/kg/milvus_impl.py b/lightrag/kg/milvus_impl.py
index a6e1b66e..55e5f9eb 100644
--- a/lightrag/kg/milvus_impl.py
+++ b/lightrag/kg/milvus_impl.py
@@ -5,6 +5,7 @@ from dataclasses import dataclass
 import numpy as np
 from lightrag.utils import logger, compute_mdhash_id
 from ..base import BaseVectorStorage
+from ..constants import DEFAULT_MAX_FILE_PATH_LENGTH
 import pipmaster as pm
 
 if not pm.is_installed("pymilvus"):
@@ -47,7 +48,7 @@ class MilvusVectorDBStorage(BaseVectorStorage):
                 FieldSchema(
                     name="file_path",
                     dtype=DataType.VARCHAR,
-                    max_length=4090,
+                    max_length=DEFAULT_MAX_FILE_PATH_LENGTH,
                     nullable=True,
                 ),
             ]
@@ -64,7 +65,7 @@ class MilvusVectorDBStorage(BaseVectorStorage):
                 FieldSchema(
                     name="file_path",
                     dtype=DataType.VARCHAR,
-                    max_length=4090,
+                    max_length=DEFAULT_MAX_FILE_PATH_LENGTH,
                     nullable=True,
                 ),
             ]
diff --git a/lightrag/operate.py b/lightrag/operate.py
index 78e11c22..d25a899f 100644
--- a/lightrag/operate.py
+++ b/lightrag/operate.py
@@ -43,6 +43,7 @@ from .constants import (
     DEFAULT_MAX_RELATION_TOKENS,
     DEFAULT_MAX_TOTAL_TOKENS,
     DEFAULT_RELATED_CHUNK_NUMBER,
+    DEFAULT_MAX_FILE_PATH_LENGTH,
 )
 from .kg.shared_storage import get_storage_keyed_lock
 import time
@@ -3154,7 +3155,10 @@ def build_file_path(already_file_paths, data_list, target):
         file_paths_set.add(cur_file_path)
 
         # check the length
-        if len(file_paths) + len(GRAPH_FIELD_SEP + cur_file_path) < 4090:
+        if (
+            len(file_paths) + len(GRAPH_FIELD_SEP + cur_file_path)
+            < DEFAULT_MAX_FILE_PATH_LENGTH
+        ):
             # append
             file_paths += (
                 GRAPH_FIELD_SEP + cur_file_path if file_paths else cur_file_path