diff --git a/pymilvus/bulk_writer/buffer.py b/pymilvus/bulk_writer/buffer.py
index 47dd5d6c6..c81e61538 100644
--- a/pymilvus/bulk_writer/buffer.py
+++ b/pymilvus/bulk_writer/buffer.py
@@ -267,10 +267,8 @@ def _persist_parquet(self, local_path: str, **kwargs):
             buffer_row_count = kwargs.get("buffer_row_count", 1)
             size_per_row = int(buffer_size / buffer_row_count) + 1
             row_group_size = int(row_group_bytes / size_per_row)
-            if row_group_size < row_group_size_min:
-                row_group_size = row_group_size_min
-            if row_group_size > row_group_size_max:
-                row_group_size = row_group_size_max
+            row_group_size = max(row_group_size, row_group_size_min)
+            row_group_size = min(row_group_size, row_group_size_max)
 
         # write to Parquet file
         data_frame = pd.DataFrame(data=data)
diff --git a/pymilvus/client/abstract.py b/pymilvus/client/abstract.py
index d5d752cda..eddf2a38c 100644
--- a/pymilvus/client/abstract.py
+++ b/pymilvus/client/abstract.py
@@ -52,6 +52,11 @@ def __pack(self, raw: Any):
 
                 self.params[type_param.key] = json.loads(type_param.value)
             else:
+                if type_param.key in ["mmap.enabled"]:
+                    self.params["mmap_enabled"] = (
+                        bool(type_param.value) if type_param.value.lower() != "false" else False
+                    )
+                    continue
                 self.params[type_param.key] = type_param.value
                 if type_param.key in ["dim"]:
                     self.params[type_param.key] = int(type_param.value)
diff --git a/pymilvus/client/prepare.py b/pymilvus/client/prepare.py
index d4ba91a14..5ffafe1ef 100644
--- a/pymilvus/client/prepare.py
+++ b/pymilvus/client/prepare.py
@@ -130,7 +130,9 @@ def get_schema_from_collection_schema(
                 is_clustering_key=f.is_clustering_key,
             )
             for k, v in f.params.items():
-                kv_pair = common_types.KeyValuePair(key=str(k), value=str(v))
+                kv_pair = common_types.KeyValuePair(
+                    key=str(k) if k != "mmap_enabled" else "mmap.enabled", value=str(v)
+                )
                 field_schema.type_params.append(kv_pair)
 
             schema.fields.append(field_schema)
@@ -187,7 +189,12 @@ def get_field_schema(
         type_params = field.get("params", {})
         if not isinstance(type_params, dict):
             raise ParamError(message="params should be dictionary type")
-        kvs = [common_types.KeyValuePair(key=str(k), value=str(v)) for k, v in type_params.items()]
+        kvs = [
+            common_types.KeyValuePair(
+                key=str(k) if k != "mmap_enabled" else "mmap.enabled", value=str(v)
+            )
+            for k, v in type_params.items()
+        ]
         field_schema.type_params.extend(kvs)
 
         return field_schema, primary_field, auto_id_field
diff --git a/pymilvus/orm/iterator.py b/pymilvus/orm/iterator.py
index 8ddaa03c5..702d744a1 100644
--- a/pymilvus/orm/iterator.py
+++ b/pymilvus/orm/iterator.py
@@ -51,8 +51,7 @@ def extend_batch_size(batch_size: int, next_param: dict, to_extend_batch_size: b
         extend_rate = DEFAULT_SEARCH_EXTENSION_RATE
     if EF in next_param[PARAMS]:
         real_batch = min(MAX_BATCH_SIZE, batch_size * extend_rate, next_param[PARAMS][EF])
-        if next_param[PARAMS][EF] > real_batch:
-            next_param[PARAMS][EF] = real_batch
+        next_param[PARAMS][EF] = min(real_batch, next_param[PARAMS][EF])
         return real_batch
     return min(MAX_BATCH_SIZE, batch_size * extend_rate)
 
diff --git a/pymilvus/orm/schema.py b/pymilvus/orm/schema.py
index 35d0d693f..c224e45cc 100644
--- a/pymilvus/orm/schema.py
+++ b/pymilvus/orm/schema.py
@@ -318,6 +318,8 @@ def __init__(self, name: str, dtype: DataType, description: str = "", **kwargs)
         self.is_partition_key = kwargs.get("is_partition_key", False)
         self.is_clustering_key = kwargs.get("is_clustering_key", False)
         self.element_type = kwargs.get("element_type", None)
+        if "mmap_enabled" in kwargs:
+            self._type_params["mmap_enabled"] = kwargs["mmap_enabled"]
         self._parse_type_params()
 
     def __repr__(self) -> str: