diff --git a/langchain/vectorstores/pgvector.py b/langchain/vectorstores/pgvector.py
index b75839d6..b29e5b3d 100644
--- a/langchain/vectorstores/pgvector.py
+++ b/langchain/vectorstores/pgvector.py
@@ -164,12 +164,12 @@ class PGVector(VectorStore):
             self.logger.exception(e)
 
     def create_tables_if_not_exists(self) -> None:
-        Base.metadata.create_all(self._conn)
-        self._conn.commit()
+        with self._conn.begin():
+            Base.metadata.create_all(self._conn)
 
     def drop_tables(self) -> None:
-        Base.metadata.drop_all(self._conn)
-        self._conn.commit()
+        with self._conn.begin():
+            Base.metadata.drop_all(self._conn)
 
     def create_collection(self) -> None:
         if self.pre_delete_collection: