[Cosmos] move system_key logic to query_iterable (Azure#22893)

* moving system_key overhead to container creation for queries to work

* Update CHANGELOG.md

* Update CHANGELOG.md

* Update database.py

* moved awaiting logic to query_iterable_async.py

* Update CHANGELOG.md

* Update database.py

Author: simorenoh

sdk/cosmos/azure-cosmos/CHANGELOG.md

@@ -12,14 +12,15 @@
 > for more details on consistency levels, or the README section on this change [here](https://github.com/Azure/azure-sdk-for-python/tree/main/sdk/cosmos/azure-cosmos#note-on-client-consistency-levels).
 
 #### Features Added
-- Added support for split-proof queries for the async client
+- Added support for split-proof queries for the async client.
 
 ### Bugs fixed
 - Default consistency level for the sync and async clients is no longer "Session" and will instead be set to the 
-  consistency level of the user's cosmos account setting on initialization if not passed during client initialization. 
+  consistency level of the user's cosmos account setting on initialization if not passed during client initialization.
   This change will impact client application in terms of RUs and latency. Users relying on default `Session` consistency will need to pass it explicitly if their account consistency is different than `Session`.
   Please see [Consistency Levels in Azure Cosmos DB](https://docs.microsoft.com/azure/cosmos-db/consistency-levels) for more details.
 - Fixed invalid request body being sent when passing in `serverScript` body parameter to replace operations for trigger, sproc and udf resources.
+- Moved `is_system_key` logic in async client.
 - Fixed TypeErrors not being thrown when passing in invalid connection retry policies to the client.
 
 ### 4.3.0b2 (2022-01-25)
@@ -28,15 +29,15 @@ This version and all future versions will require Python 3.6+. Python 2.7 is no
 We will also be removing support for Python 3.6 and will only support Python 3.7+ starting December 2022.
 
 #### Features Added
-- Added support for split-proof queries for the sync client
+- Added support for split-proof queries for the sync client.
 
 #### Other Changes
-- Added async user agent for async client
+- Added async user agent for async client.
 
 ### 4.3.0b1 (2021-12-14)
 
 #### Features Added
-- Added language native async i/o client
+- Added language native async i/o client.
 
 ### 4.2.0 (2020-10-08)
 

sdk/cosmos/azure-cosmos/azure/cosmos/aio/_query_iterable_async.py

@@ -21,6 +21,7 @@
 
 """Iterable query results in the Azure Cosmos database service.
 """
+import asyncio
 from azure.core.async_paging import AsyncPageIterator
 from azure.cosmos._execution_context.aio import execution_dispatcher
 
@@ -77,11 +78,6 @@ def __init__(
         )
         super(QueryIterable, self).__init__(self._fetch_next, self._unpack, continuation_token=continuation_token)
 
-    async def __aiter__(self):
-        if 'partition_key' in self._options:
-            self._options['partition_key'] = await self._options['partition_key']
-        return self
-
     async def _unpack(self, block):
         continuation = None
         if self._client.last_response_headers:
@@ -100,6 +96,9 @@ async def _fetch_next(self, *args):  # pylint: disable=unused-argument
         :return: List of results.
         :rtype: list
         """
+
+        if 'partitionKey' in self._options and asyncio.iscoroutine(self._options['partitionKey']):
+            self._options['partitionKey'] = await self._options['partitionKey']
         block = await self._ex_context.fetch_next_block()
         if not block:
             raise StopAsyncIteration

sdk/cosmos/azure-cosmos/azure/cosmos/aio/database.py

@@ -275,9 +275,7 @@ async def create_container_if_not_exists(
         analytical_storage_ttl = kwargs.pop("analytical_storage_ttl", None)
         try:
             container_proxy = self.get_container_client(id)
-            await container_proxy.read(
-                **kwargs
-            )
+            await container_proxy.read(**kwargs)
             return container_proxy
         except CosmosResourceNotFoundError:
             return await self.create_container(