diff --git a/src/cloudforet/cost_analysis/connector/azure_cost_mgmt_connector.py b/src/cloudforet/cost_analysis/connector/azure_cost_mgmt_connector.py
index aa082a8..1454714 100644
--- a/src/cloudforet/cost_analysis/connector/azure_cost_mgmt_connector.py
+++ b/src/cloudforet/cost_analysis/connector/azure_cost_mgmt_connector.py
@@ -120,6 +120,8 @@ def get_cost_data(self, blobs: list, options: dict) -> list:
                 offset = _PAGE_SIZE * page_num
                 yield costs_data[offset : offset + _PAGE_SIZE]
 
+            del df
+
     def list_by_billing_account(self):
         billing_account_name = self.billing_account_id
         return self.billing_client.billing_subscriptions.list_by_billing_account(
diff --git a/src/cloudforet/cost_analysis/manager/cost_manager.py b/src/cloudforet/cost_analysis/manager/cost_manager.py
index 5db318a..d67604d 100644
--- a/src/cloudforet/cost_analysis/manager/cost_manager.py
+++ b/src/cloudforet/cost_analysis/manager/cost_manager.py
@@ -24,7 +24,7 @@ def __init__(self, *args, **kwargs):
         )
 
     def get_linked_accounts(
-            self, options: dict, secret_data: dict, domain_id: str, schema
+        self, options: dict, secret_data: dict, domain_id: str, schema
     ) -> list:
         self.azure_cm_connector.create_session(options, secret_data, schema)
         billing_account_info = self.azure_cm_connector.get_billing_account()
@@ -51,7 +51,7 @@ def get_linked_accounts(
         return accounts_info
 
     def get_data(
-            self, options: dict, secret_data: dict, schema, task_options: dict
+        self, options: dict, secret_data: dict, schema, task_options: dict
     ) -> list:
         self.azure_cm_connector.create_session(options, secret_data, schema)
         self._check_task_options(task_options)
@@ -102,12 +102,12 @@ def get_data(
         yield []
 
     def _make_cost_data(
-            self,
-            results: list,
-            end: datetime,
-            options: dict,
-            tenant_id: str = None,
-            agreement_type: str = None,
+        self,
+        results: list,
+        end: datetime,
+        options: dict,
+        tenant_id: str = None,
+        agreement_type: str = None,
     ) -> list:
         """Source Data Model"""
 
@@ -139,12 +139,12 @@ def _make_cost_data(
         return costs_data
 
     def _make_data_info(
-            self,
-            result: dict,
-            billed_date: str,
-            options: dict,
-            tenant_id: str = None,
-            agreement_type: str = None,
+        self,
+        result: dict,
+        billed_date: str,
+        options: dict,
+        tenant_id: str = None,
+        agreement_type: str = None,
     ):
         additional_info: dict = self._get_additional_info(result, options, tenant_id)
         cost: float = self._get_cost_from_result_with_options(result, options)
@@ -158,6 +158,7 @@ def _make_data_info(
         tags: dict = self._convert_tags_str_to_dict(result.get("tags"))
 
         aggregate_data = self._get_aggregate_data(result, options)
+
         # Set Network Traffic Cost at Additional Info
         additional_info: dict = self._set_network_traffic_cost(
             additional_info, product, usage_type
@@ -211,8 +212,8 @@ def _get_additional_info(self, result: dict, options: dict, tenant_id: str = Non
             additional_info["Benefit Name"] = benefit_name
 
             if (
-                    result.get("pricingmodel") == "Reservation"
-                    and result["metercategory"] == ""
+                result.get("pricingmodel") == "Reservation"
+                and result["metercategory"] == ""
             ):
                 result["metercategory"] = self._set_product_from_benefit_name(
                     benefit_name
@@ -223,14 +224,14 @@ def _get_additional_info(self, result: dict, options: dict, tenant_id: str = Non
         if result.get("metersubcategory") != "" and result.get("metersubcategory"):
             additional_info["Meter SubCategory"] = result.get("metersubcategory")
             if (
-                    result.get("pricingmodel") == "OnDemand"
-                    and result.get("metercategory") == ""
+                result.get("pricingmodel") == "OnDemand"
+                and result.get("metercategory") == ""
             ):
                 result["metercategory"] = result.get("metercategory")
 
         if result.get("customername") is None:
             if result.get("invoicesectionname") != "" and result.get(
-                    "invoicesectionname"
+                "invoicesectionname"
             ):
                 additional_info["Department Name"] = result.get("invoicesectionname")
             elif result.get("departmentname") != "" and result.get("departmentname"):
@@ -239,15 +240,15 @@ def _get_additional_info(self, result: dict, options: dict, tenant_id: str = Non
         if result.get("accountname") != "" and result.get("accountname"):
             additional_info["Enrollment Account Name"] = result["accountname"]
         elif result.get("enrollmentaccountname") != "" and result.get(
-                "enrollmentaccountname"
+            "enrollmentaccountname"
         ):
             additional_info["Enrollment Account Name"] = result["enrollmentaccountname"]
 
         collect_resource_id = options.get("collect_resource_id", False)
         if (
-                collect_resource_id
-                and result.get("resourceid") != ""
-                and result.get("resourceid")
+            collect_resource_id
+            and result.get("resourceid") != ""
+            and result.get("resourceid")
         ):
             additional_info["Resource Id"] = result["resourceid"]
             additional_info["Resource Name"] = result["resourceid"].split("/")[-1]
@@ -331,10 +332,10 @@ def _get_tenant_ids(task_options: dict, collect_scope: str) -> list:
 
     @staticmethod
     def _make_scope(
-            secret_data: dict,
-            task_options: dict,
-            collect_scope: str,
-            customer_tenant_id: str = None,
+        secret_data: dict,
+        task_options: dict,
+        collect_scope: str,
+        customer_tenant_id: str = None,
     ):
         if collect_scope == "subscription_id":
             subscription_id = task_options["subscription_id"]
@@ -435,7 +436,7 @@ def _convert_date_format_to_utc(date_format: str) -> datetime:
         return datetime.strptime(date_format, "%Y-%m-%d").replace(tzinfo=timezone.utc)
 
     def _make_monthly_time_period(
-            self, start_date: datetime, end_date: datetime
+        self, start_date: datetime, end_date: datetime
     ) -> list:
         monthly_time_period = []
         current_date = end_date
@@ -465,7 +466,7 @@ def _make_monthly_time_period(
 
     @staticmethod
     def _get_linked_customer_tenants(
-            secret_data: dict, billing_accounts_info: list
+        secret_data: dict, billing_accounts_info: list
     ) -> list:
         customer_tenants = secret_data.get("customer_tenants", [])
         if not customer_tenants:
@@ -478,7 +479,7 @@ def _get_linked_customer_tenants(
 
     @staticmethod
     def _make_accounts_info_from_customer_tenants(
-            billing_accounts_info: list, customer_tenants: list
+        billing_accounts_info: list, customer_tenants: list
     ) -> list:
         accounts_info = []
         for billing_account_info in billing_accounts_info:
@@ -516,7 +517,7 @@ def _exclude_cost_data_with_options(result: dict, options: dict) -> bool:
 
     @staticmethod
     def _set_network_traffic_cost(
-            additional_info: dict, product: str, usage_type: str
+        additional_info: dict, product: str, usage_type: str
     ) -> dict:
         if product in ["Bandwidth", "Content Delivery Network"]:
             additional_info["Usage Type Details"] = usage_type