diff --git a/lightrag/kg/postgres_impl.py b/lightrag/kg/postgres_impl.py
index 1bb09305..6bb9247f 100644
--- a/lightrag/kg/postgres_impl.py
+++ b/lightrag/kg/postgres_impl.py
@@ -114,23 +114,25 @@ class PostgreSQLDB:
                         f"PostgreSQL, Failed to create table {k} in database, Please verify the connection with PostgreSQL database, Got: {e}"
                     )
                     raise e
-            
+
             # Create index for id column in each table
             try:
                 index_name = f"idx_{k.lower()}_id"
                 check_index_sql = f"""
-                SELECT 1 FROM pg_indexes 
-                WHERE indexname = '{index_name}' 
+                SELECT 1 FROM pg_indexes
+                WHERE indexname = '{index_name}'
                 AND tablename = '{k.lower()}'
                 """
                 index_exists = await self.query(check_index_sql)
-                
+
                 if not index_exists:
                     create_index_sql = f"CREATE INDEX {index_name} ON {k}(id)"
                     logger.info(f"PostgreSQL, Creating index {index_name} on table {k}")
                     await self.execute(create_index_sql)
             except Exception as e:
-                logger.error(f"PostgreSQL, Failed to create index on table {k}, Got: {e}")
+                logger.error(
+                    f"PostgreSQL, Failed to create index on table {k}, Got: {e}"
+                )
 
     async def query(
         self,